CHEMICAL TREATMENT OF AIR AND FIRE

By Charles-Guillaume SCHEE LE , Member of the Royal Swedish Academy of Sciences


WITH AN INTRODUCTION
De tokbern bergmamn , Professor of Chemistry & Pharmacy, Esquire, Member, of several Academies.
TRANSLATED FROM GERMAN
By Baron DE DIETRICH
Secretary-General of the Swiss & Graubünden , Member of the Corps of Immediate Nobility of Lower Alsace, Correspondent of the Royal Academy of Sciences
IN PARIS
Serpente Street and Hotel
Mr. DCC.LXXXI.
Under the Privilege of the Academy




INTRODUCTION OF LAT

Carl-Wilhelm Scheele, a Swedish chemist whose many discoveries earned him a reputation as a Lavoisier in France, wrote in 1777 his Chemical Treatise on Air and Fire which was translated into French and published in Paris in 1781 .

This book is not specifically a treatise on Alchemy. The experiments described therein and the conclusions inspired by them are not those of an alchemist, but rather of a scientist dealing exclusively with the actions and reactions of matter (which in no way induces elsewhere, and a priori , a lack of interest on the part of Scheele for Alchemy).

But the great interest of this book lies in the approach that its author makes to one of the major elements of alchemical practice, that is to say Air. This Air directly linked to Hermes, this Mercury which, combined with the Sun and the Moon, generates a most subtle compound...

It is indeed the Air we breathe, and not just a symbolic image.

Scheele studies Air and discovers there chemical particularities which join those of our alchemical Air. Its translator, Baron de Dietrich, summarizes it for us in one of his notes at the end of the book:

(10, §. VIII) Common Air is composed of three fluids, Fire Air, Corrupt Air & Aerial Acid; which at first seems contradictory with the title, which admits of only two kinds. But it is relative to the faculty of receiving phlogiston that the Author makes this distinction; & in this case, he doubtless includes aerial acid & corrupted Air under the same species, as neither being capable of disengaging phlogiston. We believe we should observe on this occasion, that M. Lavoisier was the first who advanced that the air of the atmosphere is composed of the union of several elastic fluids.

This happy coincidence of so-called scientific research and alchemical research could still be underlined and reinforced by this extract from the "Letter of a Philosopher on the subject of the Writing of Aristeas", written by a renowned Adept of our Art, Alexandre-Toussaint Limojon de Saint-Didier, extract devoted to the air of the air (which leads us to think that there is in the Air "something more than the Air"):

This air of the air is the fire, the water & the earth of the Philosophers, & all this is only one thing drawn from the compound as well as from the rays of the Sun & the Moon, this is what gives it these four elementary natures, between which only the two active qualities excel, namely the hot and the humid, which are all its fecundity.

LAT

*

TRANSLATOR'S OPINION

While M. Lavoisier saw himself reduced to scattering (1) only with precaution, in his various works, outlines of new principles on the physics of heat and fire, M. Wilke published them in Stockholm: Doctor Black in Edinburgh, & Doctor Irvine in Glasgow, had been imbued with it for a long time, & Doctor Crawford outdoes all these Scientists, by reducing their ideas to theory, in his Work on Animal Heat & on the Ignition of Bodies , that Mr. Magellan made known to us. M. Scheele for his part considered heat and fire as a physicist and a chemist: his aim was to analyze them. His experiences became the basis of a new doctrine which he published in the year 1777, in the Work of which the Translation is given today. It was soon after published in English, but only insufficient notions of it have come down to us in our language. M. Turgot, who cultivated Chemistry with passion, and to whom no Science was foreign, engaged me to translate this Work, of which the quotations which he found at every moment had made him feel the usefulness. The novelty of the doctrine it contains piqued his curiosity infinitely. This Translation was to be made before his eyes, and reviewed by him. I would have presented it with confidence to the Public: this feeling is no longer permitted to me. I will at least have fulfilled the views of M. Turgot & mine, if my work can be agreeable to the Academy, of which several Members seemed to me to desire the impression, & useful to French scholars.

PREFACE BY THE AUTHOR

The examination of Air has always been one of the principal objects of Chemistry: also this elastic fluid is endowed with so many particular properties that it puts those who deal with it within reach of often making discoveries. We see that Fire, that admirable product of Chemistry, cannot exist without air.

Could I have been mistaken in undertaking to demonstrate in this Treatise, which is only a Chemical Essay on the doctrine of Fire , that there exists in our atmosphere an Air which must be regarded as a constituent part of the Fire, in that it contributes materially to the flame, and which, in relation to this property, I have named Air of Fire (2). Certainly, I will not have the temerity to want to impose on my readers; the surest experiments testify in my favour. I repeated them more than once; & if I am not mistaken, I have come close enough to the goal I had set myself, of learning to know Fire. This reward from my rivals is my satisfaction.

I cannot reserve it for myself alone, and this motive determines me to publish this work, therefore I had already finished the greater part when the fine experiments of Mr. Priestley fell before my eyes. If Meyer's theory does not have many followers, his experiments nevertheless have their merit. This industrious man would no doubt have changed his way of thinking if he had acquired a clear idea of ​​Fixed Air or of Black's theory: but as, in his time, this theory was not yet fully developed, it is not surprising that he still held to the old opinion, that the pure alkalis and the absorbing earths should effervescent with the acids. Have I pushed my chemical research too far in this treatise? Already I foresee the reproaches; but I think that we cannot predict limits to this Science, only when it can no longer operate on matter, and who will demonstrate to me that light and heat should not be put in the rank of bodies, however subtle and delicate they may be? One will be able , I hope, to conclude at least from my experiments, which owe their existence to two kinds of substances (it is therefore impossible to admit that light, heat & Air are elements), which, by means of of attraction, this so incomprehensible effect of Nature, can very often be reduced to their constituent parts. the animals corrupt and that the aerial acid denatures at every moment, and which is essential to the production of Fire?

Time will teach us whether my conjectures about the constituent parts of the lands are far from reality. However, I believe that my opinion should not be regarded as a mere hypothesis: it is based on real experience; & I admit for certain that pure water in itself cannot be converted, neither by Art nor by Nature, into a dry matter, endowed with all the properties of a real earth. I know perfectly well that one can obtain an earth by repeated distillations and trituration of water. It was not enough for me to have read this fact; I had to experience this marvelous conversion for myself. I took a quarter ounce of distilled snow water; I poured it into a small glass matrass the shape and size of an egg, with a narrow neck, about an yard long: I boiled the water in it, & immediately corked this matrass hermetically; I then hung it on a lighted lamp, & I maintained the boil, without interruption, for twelve days & twelve nights. At the end of two days, the water had a whitish eye: six days having passed, it was like milk, and in twelve days it looked thick. Everything having cooled, I did not move the matrass, so that the white powder could settle, which only happened after two days. I decanted the water, whose properties were to release the volatile alkali from the sal ammoniac with which it was mixed, to be coagulated by vitriolic acid, to precipitate the metallic solutions, to green the syrup of violets, & to become gelatinous in the open air: the white earth, very loose, behaved like vitrifiable earth, mixed with very little lime. I broke the matrass, & I found that its inner surface was dull & without gloss (3), up to the height where the boiling water rose; which was not visible until the glass was dry. Could I still doubt that the water; by a long boil, decomposed the glass? Don't I have here a veritable liqueur of pebbles? It is therefore far from it that the earth that I obtained owed its origin to water. I had no more success by grinding a little distilled water for two hours in a glass mortar: it took on a milky color. When the white matter was deposited, I decanted it: this water had the qualities of pure water, indicating nothing alkaline. The white earth was nothing but pulverized glass. for two hours, in a glass mortar: it took on a milky color. When the white matter was deposited, I decanted it: this water had the qualities of pure water, indicating nothing alkaline. The white earth was nothing but pulverized glass. for two hours, in a glass mortar: it took on a milky color. When the white matter was deposited, I decanted it: this water had the qualities of pure water, indicating nothing alkaline. The white earth was nothing but pulverized glass.

FOREWORD

BY M. _ TORBERN BERGMANN
Knight of the Order of Vasa, Professor of Chemistry at the University of Uppsala, Member of the Academies of Uppsala, Stockholm , Gottingen , Berlin , GottenBourg , etc.

The history of Nature seems to have three degrees, of which Natural History properly so called is the first. It fixes our attention on the surface, and teaches us to collect useful indications on its forms, which enable us to distinguish bodies from each other. The second degree is Physics, which extends our observations further, by examining the general properties of matter (its dilation, its impenetrability, its force of inertia, &c.), with regard to its own constitution & its way of behaving. Chemistry is the highest degree: it researches the main materials, their mixtures, and their relationships to each other.

All the particular properties of bodies depending on their structure and their composition, it necessarily follows that all the operations that we perform on material things, cannot acquire their perfection without the knowledge of the history of Nature; & as these works have mainly in view our health, our needs or our approval, they gave birth to three classes of practical Sciences, Medicine, Economy & Arts. Let us consider very briefly the relation of Chemistry to each of these three Sciences.

In times when Chemistry was mainly based on ridiculous hypotheses, it was nevertheless used with zeal & blind confidence to cure all infirmities, diseases, & even to achieve immortality: then it could only to be injurious to Medicine.
We know nothing about bodies a priori ; we learn everything by observation & experience. It requires skill, a particular application & the most sincere love of truth, to imagine & undertake such that their results really explain what one wishes to discover, & not to allow oneself to be seduced. by the desire to draw general conclusions; even when we have only a small number of data, and we have not yet acquired perfect conviction. It is hardly less painful & more flattering for our self-esteem to be able to hastily discover all the progress of Nature: besides, man is naturally lazy; it is more easily prevented by ideal things than by realities; & even in our time, even when we regard the path of experience as the only one that is sure, it is always painful to admit the limits of one's knowledge: hence the inconveniences, the abuses, even the stupidities of which no Science is exempt, which unfortunately lead the greatest number in their wake.

All the functions of our body are either mechanical or chemical; those of our soul cannot be placed in one of these two classes: our food is decomposed & denatured, by means of saliva, chyle, bile, &c, passing through the mouth, the stomach, the hoses & other conduits, so that it is prepared in different parts, various materials necessary for the growth & support of our machine. Moreover, the lung, by its continual movement, introduces, through the absorbing vessels, all sorts of subtle particles, and carries them out in the same way through the exhaling vessels. The smallest disorder in all these operations of Nature suffices to establish the principle of many infirmities and diseases, which must be prevented or even destroyed by remedies which contain nothing which could be harmful to others. respects, which thwarts the main purpose, which is superfluous, or which, very innocent moreover, could inconvenience by its volume. There is therefore no doubt that it is a great advantage to be able to concentrate in one grain the virtue of many ounces. remedies, was based on chemical principles, Chemistry would certainly work miracles.

I foresee that one can be authoritative to object to me that such an important knowledge is more to be desired than to be hoped for, that in our body everything is veiled, that no glass can make our eyes penetrate it, that it is not permitted to play with the lives of men, and to expose them to the hazard of uncertain remedies, &c. All this, although true, can never dispense us from following the roads best suited to lead us to clarifications. What is difficult is not always impossible. The more effort and reflection a discovery has cost, the more it does us honor, especially when it concerns what man has most precious, health. Provided that one has really solid knowledge, one can, without danger, attempt discoveries. Advanced Chemistry has traced several new paths for itself today, and a few examples will show us what we have a right to expect from it.

Several diseases ravage & extend over very vast countries; without being contagious in themselves, they attack people of all states. They cannot come from the way of life, which is varied in subjects. There must therefore be a common cause which influences the rich as well as the poor, such as the atmosphere. We have observed, for a number of years, its gravity and its temperature: this has resulted in various explanations, but they are not sufficient to explain all its effects. It is therefore necessary to get to know its composition more closely. The vapors and the heterogeneous parts differ as much in quantity as in their nature. Chemistry teaches us that the elastic fluid which surrounds our globe is, at all times & everywhere, a mixture of three matters, namely, of good air, of corrupted air & of aerial acid. Mr. Priestley has called the first of these tunes, rather inappropriately, the phlogistic tune (4). Mr. Scheele called it, with more reason, fire air , because he is the only one who keeps the fire going, and the other two put it out.

The last species is quite commonly given the name fixed air. I believe I have demonstrated, by conclusive experiments, that it is a particular acid (5). The nature of the first kind has hitherto been little explored; it appears to be nothing but pure air, spoiled either by superabundant phlogiston, or on the contrary perhaps by an insensible diminution of the inflammable principle (6). It is still difficult to decide which of these two conjectures is true. Of these three species, aerial acid always forms the smallest part, and can rarely exceed one-fifteenth of the volume of the atmosphere, at least on the surface of the earth. The proportion of corrupted air is the greatest, and much higher than that of pure air.

The diversified action of each of these kinds of air on the animal body is still shrouded in thick obscurity. Good air, which is suitable for breathing, must produce an admirable effect, since without it one cannot live. It was believed that it contained an invigorating nourishment of absolute necessity, which has not yet been demonstrated: at least it does not seem to converge into something electric. We may soon be in a position to decide by experiment if this pure air entrains harmful parts, and especially phlogistic particles. The air which has passed through the lungs being no longer fit for respiration and resembling phlogisticated air, we can learn at the same time if the portion of the air which contains the greater part of the atmosphere is fatal when one breathes it alone, because the foreign bodies with which it is already charged, prevent it from carrying new ones from the lungs: perhaps the Aerial acid is also a poor air carrier of these particles, although it is not charged with them in advance; however, its way of acting is still undecided: we only know that it annihilates all incapacity.

I have stirred the hearts of animals which had perished by this acid before they became cold: it was impossible for me to excite the smallest irritability there by the most active menses, by fire and by scalpel. If the muscular fibers were the main cause of the movement of the lungs, it would not be difficult to pronounce on the immediate cause of its death (7): but, as they are formed of matter of an entirely different nature, it presents itself here the greatest difficulty. One could indeed easily decide by experiments, if the aerial acid & the corrupted air act in the same way: it would be necessary to examine whether irritability, which appears to be of the greatest importance for the whole economy of the animal body, has been extinguished and annihilated in animals which have promptly perished in an air corrupted by respiration, fire or other similar circumstances. The air we exhale being always charged with aerial acid, it would be necessary, to avoid any ambiguity, to perfectly purify the air corrupted by lime water before making experiments: I hope to find the occasion soon. .

If, against all expectation, the result of these experiments presents the same effects, it will seem to follow that these two fluids of different nature, act particularly, by a common impotence, to draw injurious particles from the lungs, or to supply them with life-giving nourishment. However dangerous aerial acid is to the lungs, it is however very beneficial in the first ways. Not only do ulcerated lungs endure it, but it heals them. In truth, as soon as healing takes place, his inspiration becomes dangerous. While waiting for the discoveries that remain to be made, we can always take advantage of what is already known. We can, for example, experience the air of the atmosphere very exactly in relation to its use in respiration. This discovery soon promises us the most important clarifications. We would certainly discover the cause of many phenomena that we are unable to explain now, if we made at the same time, in inhabited apartments, in hospitals and in the open air, careful observations and followed with the most rigorous accuracy. We already know that gangrene rarely spares wounds and abscesses in corrupted air, while the external use of aerial acid has not only lessened in a few days the dreadful pains of cancer, that terrible disease, but that the appalling wounds have even noticeably closed.

This is not the place to treat this important matter in more detail: I will still say, however, in a few words, that with respect to mineral waters, their analysis and their imitation, the knowledge of aerial acid has spread much light on the cure of scurvy & other internal putridities, than an accurate analysis of kidney & bladder stones, taught us to judge sanely of the remedies for the pains of stone; that the discovery of the internal nature of arsenic has made your terrible effects more understandable; it has shown us the best means of weakening its poison, and even of softening its action in order to employ it usefully. How simplified have compound remedies become! and with what certainty are the preparations of the most acute subjects made! How many absurd mixtures which decomposed by themselves have we not already proscribed!

Doesn't Chemistry daily discover a number of false theories about diseases and their cause? It was wanted, in order to be able to explain certain effects, that the sugar should contain lime, although it did not contain any vestige of it. The stones of the kidneys and the bladder must have been formed of lime, although scarcely half a per cent of it enters into their compositions, without speaking of a great number of other examples of this kind. Where would we finally be with all the kinds of secrets, charlataneries, cheatings, and many similar monsters of Medicine, if chemical analysis did not put a brake on them? It is not unfounded that the Muses have always been regarded as sisters: they are a charming symbol of the uniformity with which the Sciences can hold out their hands to each other,
After health, nothing is more essential than our subsistence.

To convince ourselves of the usefulness of Chemistry in this respect, we will limit ourselves to saying a word about Agriculture, this noble and ancient occupation. Consulting Columella & many ancient Authors who have written on Rustic Economics, we find, to our shame, that, despite the encouragements & rewards given in times nearer to us, they knew at least as much, if not more than us, it is because the Master of Nature has provided for it with infinite goodness. He wanted the grains to come with little care, and that they required more or less only purely practical knowledge.

Use and experience together soon bring the art to a certain degree of perfection. It remains at this point, until the knowledge of Nature sheds new light. It is very different to withdraw grain from a certain field, or to collect as much as can be grown. To achieve this, it is not always enough to plow, manure & divide the land; two more things are necessary independent of these mechanical means: namely, a mixture, such that it can not only furnish the plants with suitable nourishment, but also retain the humidity as long as ordinary drought requires, for nothing grows without water , even in the best-chosen grounds. Thus the best mixture is that which is prepared in a manner suitable to the nature of the ground, the situation, the climate, and the ordinary temperature, as I have elsewhere indicated in more detail. In the meantime, it will no doubt be agreed that Chemistry is of about the same importance to Agriculture and Rural Economy, as Astronomy is to Navigation .

Arts & Métiers embellish materials. There are some which are only a series of chemical operations; others are more mechanical: but I doubt there is a single one that doesn't present some problems so the perfect solution doesn't depend on Chemistry. What a succession of years has not elapsed before, by chance or little considered experiments, we have reached their present perfection, and before we have learned to counter all the inconveniences! Very often sufficient knowledge of the subject gives, without long detours, the necessary instruction. It is a great misfortune that, until now, all the practice of the Arts has been kept secret. Since the Royal Academy of Sciences began to remove this obstacle, one can count essentially on the rapid and surprising progress which the study of the History of Nature cannot fail to produce. When the true causes and their connection are not known, it is difficult to prevent or remedy the accidents or the difficulties which arise from the variety of circumstances.

It should be clearly seen that Chemistry has its own means of throwing greater light on all the manipulations of which bodies are susceptible. However, the very nature of the thing seems to have set limits to this Science: the properties of our eyes, even when they are supported or strengthened by art, cannot lead us beyond a certain point. The fineness of the instruments is not it is difficult to prevent or remedy the accidents or difficulties which arise from the variety of circumstances. It should be clearly seen that Chemistry has its own means of throwing greater light on all the manipulations of which bodies are susceptible. However, the very nature of the thing seems to have set limits to this Science: the properties of our eyes, even when they are supported or strengthened by art, cannot lead us beyond a certain point.

The fineness of the instruments is not it is difficult to prevent or remedy the accidents or difficulties which arise from the variety of circumstances. It should be clearly seen that Chemistry has its own means of throwing greater light on all the manipulations of which bodies are susceptible. However, the very nature of the thing seems to have set limits to this Science: the properties of our eyes, even when they are supported or strengthened by art, cannot lead us beyond a certain point.

The fineness of the instruments is not However, the very nature of the thing seems to have set limits to this Science: the properties of our eyes, even when they are supported or strengthened by art, cannot lead us beyond a certain point.

The fineness of the instruments is not However, the very nature of the thing seems to have set limits to this Science: the properties of our eyes, even when they are supported or strengthened by art, cannot lead us beyond a certain point.

The fineness of the instruments is not not sufficient, & in the end the best become useless. These difficulties increase further, in that it is precisely the particles which almost escape our senses; those which make the most subtle, which have the most connection between them, and which oppose the most resistance to their division, which are the most active, at the same time as they are the most energetic. That our deepest knowledge of the secrets of Nature must therefore still be imperfect!

It's all right; & it is absurd to imagine being able to discover once the first engines which the Creator used for the formation & maintenance of the material world. Such knowledge is too much above our feeble views; it is reserved for the power of the Master, and not for his creature: but it does not follow that the discoveries of phenomena by means of Chemistry are at an end . Let us only succeed in knowing perfectly the bases or next principles of the bodies, their connection and their proportion, and Chemistry will become susceptible of the greatest things.

Already in more remote times, certain materials were regarded as so simple that art had lost hope of succeeding in breaking them down: they were considered as the first bases (flamina prima). Such are above all the four elements of Aristotle, earth, water, air, fire. It is only by the most delicate operations of Chemistry that we can succeed in discovering its competition. See if we have lost all hope in this regard.

- We commonly call earth , this principle material, fixed to the fire, which remains after the fire has exercised its destructive virtue on the bodies, and which does not allow itself to be dissolved by water in its ordinary way: it is the most gross of the so-called four elements, it forms a very small portion in the bodies. What analysis has been able to determine up to now with a sort of certainty is that this earth, which is obtained at the end of very different materials, is by no means one and the same earth; that it is not homogeneous, but that it is a mixture of several earths which , depending on its nature, is more or less saline.

These various kinds of land are found on the surface of the globe in their simplest state. Six species are known, the properties of which are all different, and which, until now, could not be reduced to simpler earth, nor converted into each other; namely, the earth of heavy spar, lime, magnesia, clay, the earth of pebbles or precious stones (adelford), the distinctive characteristics of which I have indicated on another occasion. I don't know if these lands, which can be called primitive until further notice, are really different from each other, or if they are only varieties of each other; which seems more natural to me. But I have already said how dangerous it would be to restrict the order of Nature to our ideas. Conclusions should not be drawn until the data are confirmed by sufficient experiments. Perhaps patience & tireless application will once open our eyes to this object, as to many others.

We know, meanwhile, that the acid of fluorspar & the water reduced to vapor coagulate into vitrifiable earth when they meet, & the arsenical acid forming with the phlogiston of white arsenic. We can think that the earths, as well as the metallic limes, are , according to their principal matters, acids which, in the first case, have been converted into a solid substance by water, & in the last by phlogiston. . At least it is certain that Nature abounds in various acids, and that she makes special use of them in an infinite number of her operations.
Water is even more delicate & harder to break down.

On examining the thing closely, we find that the experiments by which it was first believed to convert water into earth, prove nothing. Everyone is aware that heat produces different changes in water: the particles of water very strongly attract the matter of heat, and when they have enriched themselves with it to a certain point, or are enveloped in it, this substance, thus combined, becomes so mobile that its surface always seems to seek the horizontal line. It has a lot to do with fine molten earth. If the heat is reduced, either so that the surfaces of the particles are brought into contact and their friction prevents the reciprocal movement, or that by the deprivation of one of the principle materials, there is a sufficient diminution in the spring and the repulsive force, the mass hardens, ice forms. It is not yet decided which of these two waters we are talking about here. When the ice melts, some of the heat that we employs which is equivalent to 72 degrees of our thermometer, so that a kind of saturation results from it, which causes its action to be hidden by its combination with the ice.

It is with heat as with an acid, which cannot exercise its characteristic properties when it is saturated with an alkali. It is the same with quicklime: it contains heat, but it has no effect until a stronger elective attraction emerges from it. Ice, as we have just said, becomes fluid by the absorption of 72 degrees of heat. What it acquires beyond that is superfluous, as we easily perceive, just as when we add an acid to a neutral salt. Moreover, by this superabundance of heat, the water expands, heats up, becomes more subtle, more penetrating, more mobile and lighter.

When at last the quantity of heat is so increased that it is 100 degrees, everything is converted into elastic vapours. It is true that it is already forming before this 100 degree heat; but in quantity so much the less, as the quantity of heat surpasses less the saturation in question. When these vapors separate from the mass, the latter cools because any evaporation excites, as we know, cold. Would this cold come from the fact that the increased volume would require more heat for its saturation, and that as a consequence of this effect it would be able to seize more heat than it was susceptible of before? or else the heat, which was in the beginning adherent to the water, and which has been pushed to a certain degree, would have been put in a state to concentrate, to unite in greater abundance, and consequently to remove water the portion that is most within reach?

This is pretty much what the experiments done so far on the composition of water have taught us. It clearly follows that it cannot in any way be regarded as a simple substance.

I have already mentioned Air above; I have demonstrated that what is commonly called thus is in no way a homogeneous body: it is all the less necessary for me to dwell on its nature and on that of the so-called fourth element, since it is there the purpose of this work. Mr. Scheele, its Author, has already deserved well, by various discoveries of Chemistry, and all his researches show not only deep reflections, but also a particular skill, & an indefatigable obstinacy to seek as it is necessary the truth, either by the analysis or by synthesis.
The decomposition of light, that matter of such incomprehensible subtlety in color, found by Newton, opened up a new road to the discovery of many mysteries, although this decomposition was purely mechanical. Mr. Scheele shows us a more delicate decomposition, which not only makes us acquainted with light, but also with Fire, the satisfactory explanations of which have hitherto been the cross of natural philosophy, crux philosophiae naturalis .

I have repeated, with some changes, the main experiences on which his opinions are based, and have found them to be perfectly correct. If some minor incidental circumstances were to require more precise research later on, the main one is no less good: it is based on multiple and concordant experiences. Heat, Fire & Light are, in their principle materials, the same as pure air & phlogiston: but the proportion & perhaps the manner in which they are combined, occasion their great difference. Phlogiston appears to be a really elementary matter, which penetrates most substances, and which persists in them with obstinacy. We know different ways of separating it more or less perfectly. It is pure air which, of all the substances hitherto known, is the most effective: so I have placed its sign at the head of the phlogiston column of my new table of affinities. What this air does not do quickly, is done little by little by the recourse of favorable circumstances.

It is not necessary to demonstrate, in a more extensive manner, the importance of the most delicate operations of Chemistry. To regard it as a vain subtlety, and to believe oneself entitled to despise it, one must be the prey of many prejudices and the greatest ignorance. Earth, water , air, heat, light & many other very delicate matters are found everywhere; & as long as their nature will not be known, the products of Art & Nature will be enveloped in a thick veil. There are no idle truths, veritates otiosoe . In Chemistry, the smallest of phenomena, when its causes are thoroughly investigated, has such an intimate relation with other phenomena of the highest importance, that everything is connected in the natural economy.

Finally I must also observe that this Work, made by the hand of a Master, has been finished for nearly two years, although, for several reasons which it is useless to allege here, it only appears at the present time. It resulted from it that Mr. Priestley, without having knowledge of the work of Mr. Scheele, described before him various new properties of the Air: but they are traced here in another way and in an absolutely different order.

Upsal, July 13 , 1777.

T. BERGMANN.

Naturalem causam quoerimus, et assiduam non raram & fourtuitam . Seneca.

CHEMICAL TREATMENT OF AIR AND FIRE

§. I st .
To reduce with skill bodies into their constituent parts, to discover their properties, to compose them in various ways, such is the object and the principal goal of all Chemistry.
The difficulty of carrying out these operations with all the precision they require can only be unknown to those who have never undertaken them, or who have paid only slight attention to them.

§. II.
Naturalists do not agree, up to the present, on the number of simple substances or bases of which all bodies are composed; it is in fact one of the most difficult problems to solve: several of them even despair of the discovery of the elements of bodies, a sad situation for those who take their satisfaction in studying Nature more deeply. It is very wrong to claim to draw such limited limits for Chemistry. Other Physicists believe that all corporeal Nature owes its origin to earth & phlogiston. The greater number seem entirely devoted to the Peripatetic elements.

§. III.
It cost me a great deal, I confess, to acquire clear ideas in this respect. The multiplicity of ideas and conjectures of the Authors must necessarily astonish, especially when they claim to interpret the different phenomena of Fire, and this is what attached me so much to them. I saw that not being able to make any experiment, nor obtain any effect from any means of dissolution without fire or heat, it was essential to know these matters well.
So I began, to achieve this goal, by putting aside all the explanations of Fire, and I planned a large number of experiments. I soon realized that one cannot pass a fair judgment on the different phenomena of Fire without knowledge of Air. A series of experiments proved to me that Air really entered into its composition, that it formed one of the constituent parts of the flame and the spark. I thought, therefore, that a Treatise on Fire, such as this, would be solid only so long as Air was dealt with at the same time.

§. IV .
Air is this invisible fluid that we breathe continuously, which surrounds the earth on all sides, which is very elastic, and which is endowed with gravity. It is constantly filled with a prodigious quantity of emanations so subtle that the rays of the sun make them scarcely visible, the aqueous vapors always form the greater part of them: Air is moreover united to another body resembles it in your elasticity, but which differs from it in many of its properties. Professor Bergmann rightly calls it aerial acid. It owes your existence to organized bodies destroyed by rotting or combustion (8).

§. v.
This subtle acid, which is also called fixed air , has kept physicists busy for several years. It is not surprising that the consequences deduced from the properties of this elastic acid antagonize those who were imbued with the doctrine of Paracelsus, of which they become the defenders. They think that Air in itself is unalterable, & with Hales, they believe it in truth capable of uniting with other bodies, but losing its elasticity, which it recovers when it is disengaged from this body by fire or fermentation. They realize, however, that the Air obtained in this way is endowed with properties quite different from those of ordinary Air. They conclude, without being supported by experience, that this Air has combined with heterogeneous materials from which it must be purified, by shaking it & filtering it in different fluids. We would gladly adopt this opinion, if experience proved that a given quantity of air could be totally changed into fixed air, or into another species of air, by its mixture with heterogeneous matter. Until then, I believe I am permitted to adopt as many species of Air as experience tells me. Thus, if I collect an elastic fluid, & if I observe that the property it has of expanding increases with heat & decreases with cold, while nevertheless preserving its elastic fluidity, if I find in it different properties of those of the common air, I believe myself authorized to think that this is a kind of particular air (9). if experiment proved that a given quantity of air could be totally changed into fixed air, or into another species of air, by its mixture with heterogeneous matters. Until then, I believe I am permitted to adopt as many species of Air as experience tells me. Thus, if I collect an elastic fluid, & if I observe that the property it has of expanding increases with heat & decreases with cold, while nevertheless preserving its elastic fluidity, if I find in it different properties of those of the common air, I believe myself authorized to think that this is a kind of particular air (9). if experiment proved that a given quantity of air could be totally changed into fixed air, or into another species of air, by its mixture with heterogeneous matters. Until then, I believe I am permitted to adopt as many species of Air as experience tells me. Thus, if I collect an elastic fluid, & if I observe that the property it has of expanding increases with heat & decreases with cold, while nevertheless preserving its elastic fluidity, if I find in it different properties of those of the common air, I believe myself authorized to think that this is a kind of particular air (9). I believe I am authorized to adopt as many species of Air as experience tells me. Thus, if I collect an elastic fluid, & if I observe that the property it has of expanding increases with heat & decreases with cold, while nevertheless preserving its elastic fluidity, if I find in it different properties of those of the common air, I believe myself authorized to think that this is a kind of particular air (9). I believe I am authorized to adopt as many species of Air as experience tells me. Thus, if I collect an elastic fluid, & if I observe that the property it has of expanding increases with heat & decreases with cold, while nevertheless preserving its elastic fluidity, if I find in it different properties of those of the common air, I believe myself authorized to think that this is a kind of particular air (9).
I say that such an air must preserve its elasticity in the greatest cold, because, without this condition, it would be necessary to admit an infinite number of species of air, being very probable that an excessive heat would convert all the bodies into aeriform vapours.

§. VI.
Bodies which are exposed to decay or destruction by Fire, diminish & absorb a given portion of air. Sometimes it happens that they increase it sensibly, and finally that they neither increase it nor decrease it, effects that are certainly very remarkable. Conjectures cannot determine anything positive on this subject, they are very little suited to satisfying a Chemist who wants to have the proofs in hand: also one easily feels the need to multiply experiments to clarify this secret of Nature.

§VII.
General Properties of Common Air .
1°. Fire burns for a certain time in a given quantity of air. 2°. If the Fire, while burning, furnishes no aeriform fluid, this given quantity of air is diminished by about a third to a quarter, when the Fire there is extinguished by itself. 3°. Air does not unite with common water. 4°. All species of animals enclosed in a given quantity of air, live there for a certain time. 5°. Seeds, like peas, for example, enclosed with a little water in a given quantity of air, by means of moderate heat, grow roots and rise to a certain height.
Thus any aeriform fluid which does not have these properties (and if it lacked even only one of them), is not common air.

§. VIII.
Air is made up of two kinds of elastic fluids (10).

First experience,
Having dissolved an ounce of liver of alkaline sulfur in eight ounces of water, I poured four ounces of this solution into an empty bottle, which could contain twenty-four ounces of water: I closed it with a stopper, the most exactly as I was able, I turned the bottle upside down, I placed its neck in a small vase full of water: I left it for fifteen days in this position. During this interval, the solution lost part of its color. red, & he precipitated it a little sulfur. This time over, I took the bottle, I held it with my head immersed in a large pool of water & my body above the water: I uncorked it in this position under the water, which rose rapidly there, I closed it, took it out of the water, and found that the fluid it contained weighed ten ounces. If we deduct the four ounces of sulphurous solution, there remain six ounces. In a fortnight, therefore, six parts of air out of twenty-four had been lost.

§. IX.
Second Experience.
[a] I repeated the preceding experiment with the same quantity of sulfur liver, with the only difference that I left the bottle tightly stoppered only for eight days, at the end of which I found that of twenty parts of air, it only four had been lost.
[b] Another time I did not touch my bottle until after four months: the solution was still a somewhat dark yellow, but only six parts of air had been lost, as in the first experiment.

§. X.
Third Experience .
I mixed, with half an ounce of the same solution, two ounces of caustic alkali, prepared with the alkali of tartar & quicklime, which, like the solution of liver of sulfur, did not precipitate the lime water: this mixture was yellow. I put it in my bottle, &, after letting it rest, hermetically sealed, for fifteen days, the mixture was absolutely colorless & without deposit. Having made a small opening in the cork, the Air entered it with a hiss. I conclude with reason that it was diminished in the bottle.

§XI.
Fourth Experiment.
[ a ] I took four ounces of a solution of sulfur in lime water, put it in a bottle and closed it carefully. At the end of fifteen days, the yellow color had disappeared, and of twenty parts of air, four had been lost. The solution no longer contained sulphur, but a powder had precipitated out of it, the greater part of which was gypsum. [b] Liver of volatile sulfur also decreases the volume of Air; [c] but sulfur & volatile sulfurous acid cause no change in it.

§. XII.
Fifth Experiment .
I hung pieces of linen soaked in an alkali solution of tartar over burning sulphur. When the alkali was saturated with volatile acid, I put these rags in a matrass which I stopped up as best I could with wet bladder. In three weeks, the bladder was considerably collapsed. I punctured the bladder by overturning the matrass, and holding its opening under the water; she went up there quickly, and filled the fourth part of it.

§. XIII.
Sixth Experiment.
I collected in a bladder the nitrous air produced by the dissolution of metals by nitrous acid, &, after having tied the bladder well, I put it in a matrass, the opening of which I closed with a piece of wet bladder. . The nitrous air gradually lost its elasticity, the bladder flattened, yellowed, & was corroded by the strong water. Fifteen days having passed, I pricked the bladder which closed the matrass by holding it reversed in water, which rose there with vehemence. It fills a third of it.

Seventh Experiment.
[a] I put the neck of a matrass in a jar of turpentine oil. The oil rose every day by one line in the matrass, and at the end of fifteen days it occupied the fourth part. I left the apparatus in the same state for another three weeks, without the oil rising any higher. This property is common to all oils which dry in the air, and which are converted therein into resinous matter. But turpentine & linseed oils rise rather when the matrass has first been rinsed with a concentrated caustic alkali. [b] I poured two ounces of Dippel's animal oil, colorless & clear as water, into a bottle which I carefully stoppered. After two months, the oil was thickened & black.

§. XV.
Eighth Experiment.
[a] I dissolved two ounces of March vitriol in thirty-two ounces of water. And I precipitated this dissolution with a caustic alkali. The ferruginous precipitate, of a dark green, having settled, I decanted what was clear, & I put it in the bottle above (§.VIII) with the rest of the water that I had. left on the precipitate: I sealed it hermetically. In the fifteen days (during which I had frequently shaken the bottle), this green iron lime had taken on the color of March saffron, and of forty parts of air, there were twelve lost, [b] In moistening iron filings with a little water, & keeping it for a few weeks in a tightly closed bottle, part of the air is also lost, [c] The dissolution of iron in vinegar produces the same effect on Air, & in this case, the iron precipitates in its entirety in the form of a yellow crocus, [d] The dissolution of copper in the spirit of salt thus withdrawn, also decreases Air. Light cannot burn in any of these kinds of air, so the volume has been reduced, and the slightest spark cannot be made visible there.

§. XIV.
The presence of phlogiston, this elementary flammable base, is proved by each of these processes. They show us moreover that the Air strongly attracts the inflammable principle of the bodies, that it removes it from them, and that by the passage of the phlogiston in the Air, a notable quantity of air is lost. It is certain that phlogiston is the sole cause of this effect, since, in the experiment of §. X, there no longer remains a trace of sulphur, and that the uncoloured alkali barely contains a little vitriolated tartar, according to the examination that I have made of it. THE §. XIIe proves the same: but the sulfur itself & the volatile sulfurous acid having no action on the air (§, XI, c), it is clear that the decomposition of the liver of sulfur takes place by this law of a double affinity; that the alkalis and the lime attract the acid from the sulfur and the Air from its phlogiston.
The same experiments further prove that a given quantity of air can only unite and, so to speak, become saturated with a certain quantity of inflammable principle (§. IX, b).
Does the phlogiston that these bodies have lost still exist in the air that remained in the bottle? or has the air which has dissipated become united or fixed with the liver of sulphur, the oils & other similar matters, &c? these are two very important questions.
To answer the first in the affirmative, the inflammable principle would have to have the property of depriving the air of a part of its elasticity, and of making it susceptible to being more compressed by the outside air. I thought that if this were so, such air must be specifically heavier than common air, both from the phlogiston it would contain, and from its greater density. What was my astonishment, weighing very scrupulously a very thin flask filled with this air, to see it not only hold its balance with such a volume of common air, but even be a little lighter!
I thought the last question more valid. If it had been, I should have been able to extract from the materials which I had used, the air which would have been introduced into them. None of the experiments detailed above seemed to me more susceptible to this attempt than that of §. X, because its residue is, as has just been said, vitriolated tartar & alkali: consequently, I threw this caustic alkali into lime water, to ascertain whether the lost air had been converted to fixed air. My attempt was useless, there was no precipitate. I tried again in various ways to remove the lost air from this alkaline mixture. The result having always been the same, I will not detail my experiments to avoid prolixity: but I conclude from those that I reported, fourth part of all the mass of the Air, is properly destined to attract it. It is by subsequent experiments, and not by conjectures, that we must examine what has become of this last species of air, after it has united with the phlogiston.

§. XIV.
Let us now see how Air behaves with respect to inflammable substances in combustion. We shall begin by considering combustible bodies which, when burning, exhale no aeriform fluid.

§. XVII.
First experience.
I put in a thin matrass, which contained thirty ounces of water, nine grains of urinary phosphorus: I closed the opening hermetically. I heated with a light the place of the matrass where the phosphorus was which, as it began to melt, ignited as it fled: the matrass was filled with a white cloud which clung to its walls, it was the concrete acid of phosphorus in the form of white flower. When the matrass had cooled, I opened it by holding it upside down under the water. The outside air forced the water to enter up to the competition of nine ounces.

§. XVIII.
Second Experience.
Having left in the same well-stoppered matrass several pieces of phosphorus for six weeks, or until it was ready to shine, I found that a third of the air had been lost.

§. XIX.
Third Experience.
I put three teaspoons of iron filings in a vial which could contain two ounces of water, I added an ounce of water to it, and I gradually mixed in half an ounce of oil of vitriol: the mixture fermented & warmed up vigorously. The foam having subsided a little, I closed the glass with a stopper which joined well, & through which I had passed a glass tube A (Fig. 1 era): I put this vial in a vase of hot water BB (cold water would put some obstacle to the dissolution). I held a lighted candle close to the opening of the tube. The inflammable air caught fire, & burned with a small flame of a yellowish green, I immediately took a small matrass C, which could contain about twenty ounces of water, & I plunged it deep enough in the water, so that the flame occupied the middle of the matrass. The water immediately began to rise; & when it had reached point D, the flame went out. Then the water subsided, & it was soon totally expelled. The matras contained up to D four ounces: thus the fifth part of the Air had been lost. I poured in a few ounces of lime water, to see if during the combustion any aerial acid had been produced, but I found nothing of the kind. I repeated the same experiment with zinc filings, and obtained precisely the same results. I will prove further on what the constituent parts of this inflammable air are: for, although it appears by these experiments that it is only phlogiston, there are others which testify to the contrary.
Let us now consider the way in which Air behaves with Fire, which exhales, during its combustion, an aeriform fluid.

§. XX.
Fourth Experiment .
We know that the flame of a light absorbs Air. As it is very difficult & almost impossible to light a candle in a closed matrass, I began with the following experiment. I placed a light in a bowl of water, and placed an overturned matrass over it. He immediately rose large bubbles of air on the surface of the water, which came from the expansion of the Air that the heat of the light produced in the matrass. When the flame became a little smaller, the water began to rise in the matrass; & when it was extinguished, & the matrass was cooled, I found that the fourth part was filled with water. This experiment seemed to me very inconclusive, because I was not sure if this fourth part of air had not been driven out by the heat of the flame, the outside air in contact with the water, having necessarily sought to restore the equilibrium when the flask has been cooled, by forcing to enter the flask a mass of water equal to the volume of air who had previously been driven out by the heat. So I made the following experiment.

§. XXI.
Fifth Experiment .
[a] I fixed at the bottom of the tank A a tenacious mass, two fingers thick and composed of wax, pitch & turpentine, melted together, I secured in the middle a thick iron wire which reached the middle of the matrass B: At the top C of this thread, I inserted a small candle, the wick of which I had made by twisting together three pieces of thread. I lit this candle, and I put the flask opening B on top, pushing it deep into the mass. As soon as that was done, I filled the tank with water. The flame being extinguished & the whole cooled, I opened the flask underwater in the position it was in: two ounces of water rose in it. The matrass contained one hundred and sixty ounces of water: thus there was as much lack of volume of air here as two ounces of water took up space. Has this air been absorbed by the phlogiston? or would the heat of this little flame have chased him away before I could drive this club into the tenacious mass? It appears, judging from the following, that the latter presumption holds. I took a small matrass which could contain twenty ounces of water: I burned a light in it as in the previous one, & when everything was cooled, I opened the matrass again under the water, it rose there in the same way. almost two ounces of water. Now, if, in the first matrass, there had been a diminution of a volume of air of two ounces, the absorption must have been limited in the last to the volume of two ounces. that the behind presumption takes place. I took a small matrass which could contain twenty ounces of water: I burned a light in it as in the previous one, & when everything was cooled, I opened the matrass again under the water, it rose there in the same way. almost two ounces of water. Now, if, in the first matrass, there had been a diminution of a volume of air of two ounces, the absorption must have been limited in the last to the volume of two ounces. that the behind presumption takes place. I took a small matrass which could contain twenty ounces of water: I burned a light in it as in the previous one, & when everything was cooled, I opened the matrass again under the water, it rose there in the same way. almost two ounces of water. Now, if, in the first matrass, there had been a diminution of a volume of air of two ounces, the absorption must have been limited in the last to the volume of two ounces. gros (gross is an old unit of mass, approximately 3.8 grams - LAT).
[b] I repeated the experiment with the large matrass, with the only difference that I substituted spirits of wine for the candle. I drove three iron wires of equal length into the tenacious mass attached to the bottom of the tank. These threads reached the middle of the container. I placed on these supports a square of tin, surmounted by a small vase containing spirits of wine, which I lit and covered with the matrass. I observed after cooling that the heat of the flame had expelled a volume of air equal to the space of three ounces of water.
[c] I placed on the same support a small burning coal, & let it extinguish in the same way under the container. I found after cooling that the heat of the charcoal had expelled a volume of air of three and a half ounces.
These experiments appear to demonstrate that the passage of phlogiston through the Air does not always diminish its volume, although this diminution of the Air is clearly proved by those which are reported since § . VIII to §. XIV. The sequel will teach us that this part of the Air which unites with the phlogiston and which is as it were absorbed by it, is replaced by the aerial acid, produced during combustion.

§. XXII.
Sixth Experiment.
I poured into each matrass, after the fire of the preceding experiments (§. XXI, a, b, c) had been extinguished, and everything had cooled, six ounces of milk of lime (lime water which contains more quicklime than water cannot dissolve it): I pressed my hand strongly on the opening of one of these matrass, & turned it several times from top to bottom: then I withdrew my hand a little on one side to make one day, holding the matrass overturned in the water which quickly entered it. I closed the opening tightly with my hand, I shook it sometimes in all directions in the air, and opened it again under water. I repeated this maneuver until the water no longer rose in the matrass, or until it no longer contained aerial acid. matrass: consequently the nineteenth part of air had been lost. That is quite something: but, as in the combustion of phosphorus (§. XVII) nearly a third of the air has been lost, there must be a reason why it does not doesn't absorb as much here. We know that one part of aerial acid, mixed with ten parts of common air, extinguishes Fire, and that moreover, our experiments give rise to aqueous vapors by the destruction of the oily bodies from which we have used ourselves. These vapours, dilated by the heat of the flame, settle around it. These two elastic fluids, which emerge from the flame, certainly prevent the Fire from burning longer, especially since in our matras there is no draft that can keep them away from the flame. .

§. XXIII.
Seventh Experiment.
I placed on my support (§. XXI, XVIII) a small crucible filled with sulfur which I lit, and I put the matrass over it. The sulfur being extinguished and the whole being cooled, I found that the heat of the flame had caused two parts of air out of one hundred and sixty to come out of the matrass. I poured six ounces of clear lime water into the matrass & shook it as in the previous experiment. I saw that the sixth part of the whole Air had been lost during the combustion. However, the lime water was not precipitated: which proves that if sulfur does not exhale fixed air while burning, another substance emanates from it which has some connection with air. This substance is the volatile sulfurous acid which seizes the space abandoned by the air at the moment of its combination with the phlogiston. It is remarkable that phlogiston so considerably diminishes the volume of the air whenever it combines with it, either by separating it from bodies by combustion, or by employing any other means for get out of it.
Experiments which prove that the two species of elastic fluid which compose the common air , can be reunited , after they have been separated by the phlogiston (11).

§. XXIV.
I observed (§. XVI.) that I could not find the lost Air. One could tell me in truth that the lost Air is hidden in that part of the Air which cannot unite with the phlogiston, for this residue being lighter than the common air, it could owe this lightness to the phlogiston combined with lost Air, as other experiments have already made us think; but the phlogiston being a matter, and matter always presupposing a weight, I doubt that this hypothesis is founded. Besides, without going into greater detail, I will demonstrate that the combination of air with phlogiston is such a subtle compound that it is capable of penetrating the imperceptible pores of glass, and dispersing it in all directions. in the air.

§. XXV.
How many times have chemists distilled the spirit of nitre with oil of vitriol and saltpetre? It is impossible that they did not notice that this acid turns red at the beginning, white & colorless towards the middle of the distillation, & that at the end it becomes red again, & even of such a dark red, that 'you can no longer see through the container. It is good to observe that by letting the heat gain too much at the end of the distillation, the whole mixture bubbles up in such a way that it passes entirely into the receptacle; & what should be noted above all is that during this inflation, a kind of Air comes out of it which deserves the greatest attention. If you use black oil of vitriol, not only is the nitrous acid which passes at the beginning of a much darker red than when this oil is white: but if you carry a light in the container when about an ounce of acid has passed, it will off immediately; while if you put your light on towards the end of the distillation, & when the mixture is foaming strongly in the blood-red vapors which fill the vessel, not only will the light continue to burn, but the flame will be much lighter than in common air. It will be the same if, towards the end of the distillation, one lutes with the retort a container filled with an air in which the but if you carry a light into the receptacle when about an ounce of acid has passed, it goes out immediately; while if you put your light on towards the end of the distillation, & when the mixture is foaming strongly in the blood-red vapors which fill the vessel, not only will the light continue to burn, but the flame will be much lighter than in common air. It will be the same if, towards the end of the distillation, one lutes with the retort a container filled with an air in which the but if you carry a light into the receptacle when about an ounce of acid has passed, it goes out immediately; while if you put your light on towards the end of the distillation, & when the mixture is foaming strongly in the blood-red vapors which fill the vessel, not only will the light continue to burn, but the flame will be much lighter than in common air. It will be the same if, towards the end of the distillation, one lutes with the retort a container filled with an air in which the but the flame will be much brighter than in common air. It will be the same if, towards the end of the distillation, one lutes with the retort a container filled with an air in which the but the flame will be much brighter than in common air. It will be the same if, towards the end of the distillation, one lutes with the retort a container filled with an air in which the fire cannot burn: half an hour later, a light will burn in the air it contains.
Are nitrous acid vapors naturally red? Allow me to raise this question, because there are people who point to the redness of this acid as one of its distinctive marks. The colors of nitrous acid are accidental. If one distils a few ounces of fuming nitrous acid at a very gentle fire, the yellow color separates from it, passes into the receptacle, and the residue which is in the retort is white and colorless like water. This acid nevertheless has all the principal properties of nitrous acid: it lacks only the yellow color, and this is what I call pure nitrous acid. As soon as he touches an inflammable substance, he blushes more or less. This red acid is more volatile than pure acid. Hence it is that mere heat can separate them from each other, and this is why it is necessary that, in the distillation of Glauber's nitre spirit, the volatile spirit must pass first, and after it. the uncolored acid: but why does this acid reappear under the blood color at the end of the distillation? Where does this red acid come from, doesn't it also pass from the beginning of the operation? Where does it get its phlogiston from? this is the knot.

§. XXVI.
I said in the preceding § that the light went out in the container at the beginning of the distillation, the reason for this is found in the experiment reported in §. XIII. The nitrous acid which passes into vapors seizes the phlogiston, the presence of which is proved by the black color of the oil of vitriol. As soon as this is done, it encounters Air which in turn removes the flammable principle from this phlogistic acid: thereby a portion of the Air contained in the container is lost, this is why the Fire that one plunges into it is extinguished there (§. XV).

§. XXVII.
Nitrous acid is capable of becoming charged with phlogiston in different proportions; each of these proportions gives it other properties [a]. If it is completely saturated with it, a true Fire is produced which destroys it completely [b]. If it is there in lesser proportion, the acid is converted into a sort of air which refuses to unite with the alkalis and the absorbent earths, and which only mixes with the water in very small quantities. . If this aeriform nitrous acid comes into contact with Air, the latter removes its phlogiston: it loses its elasticity (§. XIII). The vapors redden, and the Air undergoes a change as natural as it is remarkable, that it not only diminishes, but also that it heats up [c]. If the nitrous acid is united with still less phlogiston, it is likewise converted into a kind of invisible air like Air, but which unites with the alkalis & some kinds of earths, & which produces by this union true neutral salts. But this phlogistic acid is so feebly combined with these absorbent substances, that it can be driven out of them by simple vegetable acids. It is in this way that it is united to the reddened saltpetre with the fire and the antimonial nitre. If nitrous acid in this state encounters Air, it likewise loses its elasticity, it is converted into red vapours, and if a certain quantity of it is mixed with water, the latter becomes blue, green or yellow[d], When pure nitrous acid is united with very little phlogiston, the vapors merely acquire redness. It lacks the power to expand; however it is more volatile than pure acid. Nitrous acid retains this small quantity of phlogiston so strongly that Air itself, this substance which has so much affinity with it,

§. XXVIII.
These principles established, let us see if it would not be possible to explain the phenomenon mentioned in §. XXV; know, that the Fire burns with such a lively flame in the vessel at the end of the distillation: & the Air, especially that part of the Air by means of which the Fire burns, which (according to previous experiments ) forms only the third part of the common air, would it not have reached the container by means of distillation? Must not this species of air, which, when combined with phlogiston, entirely escape the senses, reappears when this combination meets a body which has more affinity than it with phlogiston? Could one reasonably hesitate to believe that this is positively what happens in the distillation of the spirit of fuming nitre? Did I not say in §. previous, letter d , & daily experiments do not demonstrate it, that it is not easy to separate the more or less redness from the nitrous acid, whatever be the force with which the Air attracts the superabundant phlogiston of this acid. This attraction produces heat ( see §. XXVII, letter b ); which gives me reason to suspect that it arises from the heat of each combination of the phlogiston with the Air, & consequently, that the heat is composed of this species of air which forms the third part of the common air ( §. XVI.) & the flammable principle. It is this heat which, in the distillation of concentrated nitrous acid, is decomposed & reduced to its constituent parts. It owes its presence to the Fire with which distillation is maintained. It forms first of all from Air, without which no Fire can exist, and from the phlogiston of coals: it penetrates the capsule, the sand and the retort, where it encounters a substance which attracts phlogiston more strongly than phlogiston. 'Air with which it is combined: thus the heat is decomposed; & by this decomposition, the nitrous acid acquires a dark redness, the Air which was there divided in an incomprehensible way, resumes its properties. The nitrous acid, which the heat has made more elastic, draws this air into the container, where it can again attract phlogiston, and as this species of air is found in greater proportion in the receptacle than in the common air, it is not surprising that the flame burns more vigorously there. This opinion seems to me at first as extraordinary as it may seem strange to my readers. Being convinced that it is not a simple hypothesis, but one of the most constant truths, I will seek to demonstrate it by new experiments.

§. XXIX.
I took a glass retort which could hold eight ounces of water; I distilled the fuming nitre spirit in the ordinary way. This acid turned red at the beginning, then without color, and at the end it became red again. As soon as I noticed that this color reappeared, I took off the container; I substituted a bladder emptied of air, into which I had poured a little thick whitewash, to prevent the bladder from being corroded: I then continued the distillation. The bladder dilated little by little, then I let everything cool: I closed the bladder with a string, and detached it from the neck of the retort. I filled, from the Air contained in the bladder, a glass which contained ten ounces of water (§. XXX, letter e ): I placed a small light there which immediately burned with a great flame & dazzling vivacity: I mixed one part of this air with three parts of air in which the Fire no longer burned, & I obtained a Air absolutely similar to common air. This Air being essential to the birth of Fire, & forming about a third of the common air, I will name it hereafter, to abbreviate, the Air of Fire , & I will give the name of Corrupted Air which has already been attributed, to that which is of no use to combustion, and which forms approximately two-thirds of the common air.

§. XXX (12).
As one could ask me in what way I transfer the Air, I believe myself obliged to describe it. My apparatus & my vases are as simple as possible: they are matrass, retorts, glass bottles & ox bladders. When the bladders are still fresh, they are rubbed & Air is blown into them, so that they are very extended: they are tied tightly, & they are hung up to dry. If they remain well stretched, I am sure that they are suitable for the use for which I intend them [a]. take a flexible bladder, coated inside with a few drops of oil, I put a little iron filings, tin or zinc; I express, my best on a small vial which contains a little etching; then I untwist the bladder a little, so that only a few filings fall into the glass at a time: the bladder expands as the filings dissolve. When I have the desired quantity of this Air in my bladder, I tie it tightly near the opening of the vial, & untie it [b]. If this phlogisticated nitrous acid is mixed with aerial acid, which happens when the acid of saltpetre is distilled on sugar, I attach to the end of the neck of the retort A (Fig-13) a bladder softened in water, taking care to scrape the neck of the retort a little with a flint to prevent any passage of Air (the retorts that I use contain from half an ounce to three ounces of water & not beyond, but their collar is one yard long (13), So that the bladder attached to it is not spoiled during the operation by the heat of the furnace and the vapours, I pour a little whitewash into the bladder, & I express its air as much as possible. This lime absorbs the aerial acid during distillation, & the phlogisticated nitrous acid remains intact [c]. The method described above, letter a , also serves me to collect the aerial acid & the inflammable air of the sulfur of which I will speak below. These two kinds of Air pass, in a few days, through the bladder when it is humid, it even happens that the Air which surrounds it is. This does not take place, if the bladders & Air are dry. I get the same flammable air from metals, like iron, zinc, &c, with the only difference that I put the retort in hot sand. This Air is even more subtle than the previous ones: in a few days it penetrates the very fine pores of the bladder, although it & the Air are dry. I have experienced this very often much to my displeasure [d]. It frequently happens to me to collect the Air in bladders without using a vial: I put in a softened bladder AA (Fig. 4) the materials from which I propose to obtain the Air, chalk, for example , I tie the bladder with a BB yarn over the chalk. I pour on top an acid dissolved in water, & I express the Air of the bladder as best as possible; finally I close it at the top in CC, I open wire B: the acid flows on the chalk; it disengages the aerial acid, so that the bladder expands [e]. If I wish to transfer Air from a bladder into a matrass, into a glass, into a retort or into a bottle, I fill this vessel with water, & I put a cork in it that closes well; I fasten the opening from C to D very tightly (Fig. 4) of the bottle, which I turn over so that the bladder is at the bottom & the bottle at the top. I then take the bottle with my left hand, and I remove the cork with my right hand, which I hold firmly between my fingers, until the water in the bottle has flowed into the bladder, and the Air of it is mounted in the bottle, then I put the cap back on & I detach the bladder from the bottle. When I want to keep this Air for a long time, I put the neck of the bottle in a vase of water. If the bladder contains aerial acid, or another Air capable of combining with water, and if I want to make this combination very pure, I fill a bottle with cold water; & when the bladder is adapted to it, I let in about a quarter of the water, & I put back on the bottle the cork which I had kept closed in the bladder: then I gently stir the bottle, & the Air is absorbed by the water, after which, I slightly open the cork, so that the air from the bladder can rise in the bottle to fill the vacuum that has been produced there, without water flowing into the bladder. I put the cork back on the bottle, & I shakes off the water it contains. I repeat this maneuver two or three more times, after which the water is saturated with this air.
If I want to mix two kinds of Air in a matrass or a flask, I begin by pouring into the bladder as much water from the flask that is filled with it as I want. to have air, according to the proportion that I desire; I then attach a vial above a bladder filled with the other Air; I let the remaining water flow into it, and as soon as the last water has come out, I put the stopper on the vial. If I want to transfer the Air that I have collected in a bottle into a bladder, I reverse the maneuver; I fill the bladder with as much water as I want air in it, I tie it up, I then tie it to the neck of the bottle: I open the string, I pull the cork off the bottle ; I let the water from the bladder flow into it: I retie the bladder containing the Air that was in the bottle so I untie it. [a] When I have two mixed airs in the same bottle, that one of the two can be absorbed by water or lime, & that I want to know how many there are of each species, I attach to my bottle a bladder which contains as much cream of lime as is needed to fill the bottle, which I uncork to let the water run through it or whitewash; then I turn the bottle upside down, pour the water or whitewash into the bladder, & I repeat this alternative transvasion several times: finally the quantity of whitewash which remains in the bottle tells me the volume of air which it has absorbed.
Such are the methods which I have used for my experiments on the different airs, they will not suit everyone perfectly, because they do not give very exact results: but they have satisfied me in all my researches.

Continuation of the Experience reported in §. XXVIII, with Proofs that Heat is Composed of Phlogiston & Air of Fire .

§. XXXI.
One could say that the air obtained in the experiment of §. XXVIII, is only dry nitrous acid, converted into elastic vapors: but, if this opinion were correct, this air should not only be corrosive, but it would also have to form saltpeter with the alkalis, which does not does not happen. However, this objection would retain a certain weight, if it were impossible for me to demonstrate that several bodies furnish, during distillation, the same air as nitrous acid, but the proofs are not lacking to me.
I have shown, in a Treaty of Manganese, inserted in the volumes of the Royal Academy of Sciences of Stockholm, year 1771, that this mineral was not soluble in any acid, unless one added an inflammable material which communicated its phlogiston to the manganese, and could provide it with the means of introducing itself into the acids. I have shown, in the same Treatise, that vitriolic acid combined in a strong distillation with manganese reduced to powder, which made it soluble in water, and that, when this manganese was separated from the vitriolic acid by the aid of precipitants, it gave the least doubtful marks of the presence of phlogiston. I therefore concluded from this insight that the heat contained a phlogiston, & this conjecture has come true. Having said that nitrous acid decomposes its heat, because it has a greater affinity with phlogiston than the Air of Fire, & having observed that one of the properties of manganese is to attract phlogiston even more strongly than nitrous acid, I will not hesitate to advance that manganese decomposes heat by the same principle as nitrous acid. I can all the less doubt it, since I observed, several years ago, that when the current of air carries & having observed that one of the properties of manganese is to attract phlogiston even more strongly than nitrous acid, I will not hesitate to advance that manganese decomposes heat by the same principle as nitrous acid. I can all the less doubt it, since I observed, several years ago, that when the current of air carries & having observed that one of the properties of manganese is to attract phlogiston even more strongly than nitrous acid, I will not hesitate to advance that manganese decomposes heat by the same principle as nitrous acid. I can all the less doubt it, since I observed, several years ago, that when the current of air carries the charcoal dust on the surface of a mixture of manganese & vitriolic acid which is calcined in an open crucible, this subtle charcoal ignites at the same moment with great brilliance. As a result, I made the following experiments.

§. XXXII.
First experience.
I mixed with fine manganese powder, as much concentrated oil of vitriol as was needed to make a thick porridge: I distilled this mixture over an open flame, in a small retort, I fitted it with a bladder emptied of air instead of container, in which I had poured a little whitewash (§. XXX, letter b ), so that the vapors which would rise would not attack it. As soon as the bottom of the retort reddened, air passed through which gradually dilated the bladder. This air had all the properties of pure Fire Air.

§. XXXIII.
Second Experience.
I obtained the same air by distilling, as in §. previous, two parts of finely powdered manganese, with one part of phosphoric acid from urine.

§. XXXIV .
Third Experience.
[a] I dissolved white magnesia which is commonly used in Medicine in aquafortis, & evaporated this solution to dryness: I put the salt which came from it to distil in a small retort, as in § . XXXII. The nitrous acid separated from the magnesia in sanguineous vapors, even before the retort was red, & at the same instant the bladder dilated. The Air I got from it was my Fire Air.
It is thus that one daily sees the acid in fire separate from the metals under this color, when one makes them leave this menstruation by heat.
[b] I distilled mercurial nitre in the same way, until the nitrous acid had separated from the red precipitate, & I also obtained the Air of Fire. Nitre is by itself capable of decomposing heat. Where does the bubbling of molten nitre come from, darkly reddened in a crucible? Neither smoke nor vapors can be seen rising from it, and yet the dust of coal which flies over the uncovered crucible ignites and sheds such a brilliant light. How does it come about that this saltpeter, held thus for half an hour red & in fusion in a glass retort, becomes moistened & falls into deliquescence in the open air when it is cooled, without however that one discovers remains of alkali (§. XXVII, letter c )? Whence comes, finally, that this saltpeter in deliquescence releases its volatile acid so easily when it is rubbed or mixed with vegetable acids? I had no more difficulty in resolving these questions, when I learned to know the integral parts of heat. How advanced would we be if the chemists of the last century had judged worthy of special examination the elastic and aeriform fluids which manifest themselves in so many operations? They wanted to see everything bodily & collect everything by drops in a container. We are currently more informed about this object, and we have begun to examine Air. Could we not see its usefulness? The following experiment will prove that nitre by itself can decompose heat.

§. XXXV.
Fourth Experiment.
I put in a glass retort an ounce of purified saltpetre to distil it, & I used a moistened & emptied bladder instead of a container (Fig. 3). As soon as the nitre began to redden, it began to boil, and at the same instant the bladder was dilated by the air which passed through it. I continued the distillation, until the boiling ceased, and the nitre was on the point of penetrating the softened retort. I obtained in the bladder the Air of pure Fire: it occupied the space of fifty ounces of water. It is the best and least expensive method of obtaining this kind of air.

§. XXXVI.
Previous experience might give rise to the following doubt. If nitrous acid attracts phlogiston more strongly than the air of Fire, why does the nitre cease to boil at the end, & why does it not seize the inflammable principle in sufficient abundance to alkalize? But let us reread for any answer what was said in §. XXVII, letter d. What other substance than heat would penetrate the retort here? Would one think that light played a part in it? The distillation of the spirit of fuming nitre would prove the contrary, as well as the experiment of § XXXIV, a . In these experiments, our fire air is produced, although the materials and the retorts do not redden.
Let us now see if there are not other bodies capable of decomposing heat. These observations lead us to the phenomena which the limes of perfect metals present to us in fire.

§. XXXVII .
It is so decided that the acid of saltpetre and the dephlogisticated marine acid deprive the perfect metals of the inflammable principle to which they owe their metallic luster, that I believe it superfluous to allege proofs of this. The quantity of air bubbles which form in nitrous acid on the surface of gold, silver, mercury, and which burst under a yellow color as soon as the air touches them (§. XXVII. ), are palpable proofs of this truth. Nevertheless, as it has been noticed that these metallic limes, separated from their menses, are reduced by simple heat, without addition of phlogiston, it has been concluded that the strongest menses are incapable of depriving the perfect metals of their principle. flammable. Others, on the contrary, convinced of the calcination of these metals by the acids, thought that the little phlogiston which they lack, separated from the carbons, penetrated the crucible, and was incorporated with these limes, an opinion which comes fairly close to reality: but it should be known that the phlogiston does not separate from any body, unless it is immediately in contact with that which attracts it more strongly. Now, the phlogiston of carbons having no action on the crucible, it cannot immediately touch the metallic lime, and yet the reduction is done well. There must therefore be a but it should be known that the phlogiston does not separate from any body, unless it is immediately in contact with that which attracts it more strongly. Now, the phlogiston of carbons having no action on the crucible, it cannot immediately touch the metallic lime, and yet the reduction is done well. There must therefore be a but it should be known that the phlogiston does not separate from any body, unless it is immediately in contact with that which attracts it more strongly. Now, the phlogiston of carbons having no action on the crucible, it cannot immediately touch the metallic lime, and yet the reduction is done well. There must therefore be a other matter capable of restoring to the metallic limes the inflammable principle of which they are deprived. Considering heat only as a simple substance, we cannot attribute this reduction to it: for if it were, it would also have to bring about that of the limes of the imperfect metals. But, in reflecting on the constituent parts of heat, we will certainly not doubt that by its phlogiston it cannot produce this change in metallic limes. If this is constant, it is also certain that it must free itself from the Air of Fire during this reduction, and this by the principles contained in §. previous ones.

§. XXXVIII.
Fifth Experiment.
I took a solution of silver in nitrous acid, I precipitated it with the alkali of tartar; I washed & dried the precipitate, I put this silver lime in a retort to reduce it over an open fire: I attached an empty bladder to the neck of the retort, immediately the bladder was dilated by the Air which was released. The distillation being completed, I found in the retort the silver lime half melted, and having a metallic luster. Having procured this precipitate by the alkali of tartar which is always united with a great deal of aerial acid, and this acid attaching itself to the silver lime while it precipitates it, this acid had to be also in the bladder. I took it out with whitewash (§. XXX, letter i ): I was left with half the Air,

§. XXXIX.
Sixth Experiment.
I precipitated with the alkali of tartar a solution of gold in aqua regia & I reduced the gold lime as above, after having watered down & dried it. I obtained the same air from Fire, but no aerial acid , which is not surprising, the saturated solution of gold making effervescence with the alkali, and the solution of silver not making any.

§. XL.
Seventh Experiment.
We know that the red precipitate of mercury resumes its fluid form without the addition of phlogiston; but mercury being really deprived of its inflammable principle by the vitriolic and nitrous acids, it must necessarily have recovered it, as soon as its metallic property is restored to it.
[a] I poured a solution of tartar alkali drop by drop into a solution of corrosive sublimate: I washed & dried the reddish-brown precipitate that I obtained from it, I put it in a small retort, covered with an emptied bladder of air, to reduce it over an open fire. As soon as the lime began to redden, the bladder was dilated, and the mercury rose in the neck of the retort. The Fire Air I got had a bit of air acid in it. [b] Mercury, converted into lime by nitrous acid or the red precipitate, gave, with the same process, the same result: but the Air of the fire was pure, without mixture of aerial acid.

§. XLI.
Eighth Experiment.
I have demonstrated, in a Treatise on Arsenic which I have communicated to the Royal Swedish Academy of Sciences, that this poisonous substance is composed of an acid which is specific to it and of phlogiston: I have shown in the same treatise that this acid could be entirely sublimated into arsenic by simple sustained heat. Although I therefore clearly saw the reason, I did not want to say it, to avoid being prolix. I put a little of this fixed arsenical acid in a small retort, covered with a bladder, to make the distillation. When the acid was in fusion, & when it blushed white, it entered into boiling, during which arsenic rose in the neck of the retort, & the bladder was dilated. I pushed the heat as long as the retort held it. The Air I got was Fire Air. I have also made mention in this Treatise of a particular explosion which took place during the distillation of zinc with arsenical acid. The explanation of this phenomenon is quite simple, when one is convinced that in this case the Air of Fire is found in the retort in the greatest state of purity, while the zinc is quite red. What more is needed for its inflammation?
I have very often taken great pleasure in contemplating the sparks of dazzling brilliance, produced by heat alone, in a retort, by reducing metallic limes with which very little charcoal dust is mixed.
Let us now see if this air of Fire is not the same air which, in §. VIII, XV, was lost without Fire, & in §. XVII, XXIII, with Fire.

§. XLIII.
First experience.
I filled with air from the Fire (according to the method described in §. XXX, letter a ) a vial which could contain sixteen ounces of water: I overturned it in a jam glass, full of a solution of sulfur liver. The solution rose a little in the vial every hour, and in two days it filled it completely.

§. XLIII.
Second Experience.
I mixed in a bottle fourteen parts of the Air from which the Air of Fire had been separated by the liver of sulfur (§. VIII), and which I named (§. XXIX) corrupted air, with four parts of air of Fire: I left the bottle open, and overturned it in a vase which was also filled with a solution of liver of sulfur. Fifteen days having passed, the four parts of Air du Feu were lost, and the solution had replaced them in the bottle.

§. XLIV.
Third Experience.
After filling a vial with Fire Air, I poured into it a little uncolored animal oil; I corked it hermetically. After a few hours, the oil was already brown, and the next day it was black. It is very difficult to preserve this oil's white color in the pharmacies: one is forced to pour it into small jars, and to guarantee it with the greatest care of the Air. If we mix this uncolored oil with some acid, even when it is diluted in water, the oil, like the acids, turns black after an hour: even vinegar produces this effect. The only cause that this oil blackens so quickly in the Air, is that the Air of Fire, contained in the Air, removes the phlogiston from the oil,

§. XLV.
Fourth Experiment.
[a] I put a piece of urine phosphorus in a vial containing seven ounces filled with Air of Fire: I closed it with a stopper, I heated with a light the place where the phosphorus was, which ignited & cast a very clear flame. The vial shattered into pieces as soon as the flame was extinguished.
[b] The flask of the previous experiment being very thin, I repeated it with a thicker flask, & when everything had cooled, I wanted to remove the stopper under water. This was impossible for me, so strongly did the outside air press the cork in the vial. So I sank it completely: the water rushed into it and filled it almost entirely. As the first vial was very thin, the rupture could only be attributed to the pressure of the outside air, [c] Having mixed Corrupted Air with a third of Fire Air, & having burned a piece of phosphorus, only a third of the Air was absorbed either.

§. XLVI.
Fifth Experiment.
I repeated the experiment of §. XIX, with the only difference that I took longer tubes, and that I filled the matrass with Air du Feu. It was pleasant to see the water rising little by little in the flask, the flame went out, when seven-eighths of the flask was full of water.

§. XLVII.
Sixth Experiment.
I placed on the supports (§. XXI, let. e ) some burning coals, & I covered them with a matrass full of air from the Fire: the coals had barely reached the Air of the matrass, when their fire broke out. 'anima.
When everything was cool, I made an opening at the bottom of the matrass, the fourth part of which filled with water. But, when with the help of whitewash I had removed the aerial acid that the rendering of Air contained, the water occupied three quarters of the matrass, & a light was still burning in this air.

§. XLVIII.
Seventh Experiment.
I wanted to see how the Air of Fire acted with the sulfur in the experience of §. XXIII. As soon as the inflamed sulfur came into contact with the Air of the Fire that the matrass contained, the flame grew larger and brighter. The fire being extinguished, the water from the tank had made its way through the cake, & had filled three-quarters of the matrass. As I made use for these last three experiments of a matrass which only contained a volume of air of thirty ounces of water, I was obliged to arrange my support (§. XXI) accordingly.

§. XLIX.
If Corrupt Air is lighter than Common Air, as I have argued (§. XVI), Fire Air must be heavier than Common Air. Indeed, a volume of Fire Air of twenty ounces of water weighs almost two grains more than an equal volume of common Air.

§. I.
These experiments prove that this Air of Fire is precisely the same Air of Fire that causes the Fire to burn in common Air. It is united in common air to an air which seems to have no affinity with phlogiston, which is somewhat opposed to inflammation, which is moreover so prompt and so lively. Indeed, if the Air Commun was not composed only of Fire Air, water would be of very little help in fires. Air Acid, combined with Fire Air, produces the same effect as Corrupted Air. I mixed one part Fire Air with four parts Air Acid; the light still burned quite well in this mixture. Heat, interposed in the pores of inflammable bodies, could not produce all the heat that Fire makes us feel, & I believe I am not mistaken in concluding from my experiments, that (14) fiery heat is only produced, during the combustion of Fire, by Air & the phlogiston of inflammable bodies; & if this new elastic product, infinitely subtle, comes to touch another body, which attracts the phlogiston more strongly, be decomposed: the experiences of §. XLV, letter b, & §. XLVI, prove it in the most obvious way, since the totality of what was in the matrass has disappeared.
Let us now examine whether the Air of Fire which we have lost without fire, in the experiments of §. VIII-XV” has really been converted into heat. In truth, one does not feel any heat to the touch: but the tenth §. proves to us without reply that in this circumstance there was a combination of the Air of Fire with the phlogiston. It is not necessary to rely on touch to properly judge the heat, the thermometer alone can make us appreciate it. Sulfur only burns for about three minutes in a given quantity of air, & yet an equal quantity of air can remain in contact with the liver of sulfur for some weeks, before the Air of the Fire in it. be totally separate. It is therefore necessary, in this case, that the heat, which is however formed at each instant, is only very small: but what more do you need? There are experiments where the Air is already absorbed in half this time: then the proportion of heat must be doubled. There are others in which this heat becomes sensible to the touch: so the Air of Fire disappears from it in an hour. Here are my experiences in this regard.

§. LI.
First experience.
I mixed a strong solution of liver of sulfur with enough powdered chalk, so that the mixture became almost a dry powder: I put this powder in a jam glass outside my window, with a thermometer. Two hours later, when the thermometer and the powder had acquired the same degree of heat , I placed the thermometer in the glass in the middle of the powder. In a few minutes, the spirit-of-wine had risen a little in the tube. I took the thermometer out of the powder and placed it close by: the liquor immediately went down. I put it back in the glass, and the spirit of wine rose again. The next day the powder no longer caused any sensation on the thermometer. This powder, which was yellow the day before, had become white, and the addition of a few acids did not give off the hepatic odor, which proves that the sulfur was destroyed. It is therefore not surprising that no more heat was produced.

§. LII.
Second Experience.
[a] The iron filings, moistened with a few drops of water, also caused the liquor to rise in the thermometer. This experiment was repeated several times three days in a row, with the same filings, and equal success. [b] The oil of turpentine absorbs the Air, it would seem that it must also produce heat. I mixed a little of this oil with powdered chalk, so that this mixture became a loose powder , & when the thermometer had the same degree of heat as the mixture, I placed it there: but the liquor neither rose nor fell. The oil of turpentine evaporating considerably, and all evaporation absorbing the heat of the air, would it not happen in this case that the cold, caused by the evaporation, would compensate for the heat produced? In fact, if it were not, the liquor in the thermometer would have to drop.
I had mixed the liver solution of sulfur & the oil of turpentine with chalk, so that the air could touch the phlogiston at a greater number of points, and thereby excite a more sensible heat.

§. LIII.
Third Experience.
The Air of Fire being the only portion of the common air which can compose heat by uniting with the phlogiston, I wanted to see if the heat produced would not be more sensitive, using only Air for these experiments. fire. My doubt was soon cleared up; for, having filled a twelve ounce jar with Fire Air, & having kept it tightly closed, for four hours, beside a thermometer & a mixture of pulverized chalk & solution of liver of sulfur, I put the powder in the jar; I placed the ball of the thermometer in it, I sealed the jar around the tube with wax. Immediately afterwards, the liquor rose in the tube twice as much as it had risen in the same mixture in the open air.

§. LIV.
Fourth Experiment .
The heat produced by a mixture of iron filings, sulfur and water is solely due to the union which the phlogiston of iron has contracted with the Air of Fire. I mixed three parts of iron & one part of sulphur, with as much water as was needed to make a wet powder: I divided this mixture into two portions. I filled a vial with a hermetically closing stopper with one: I exposed the other to the open air in a jam glass, which grew so hot in two hours that I could not keep it for long. glass in hand, while the vial did not heat up at all, yet this portion of the mixture was blackened like the other. A few weeks later, I threw on a piece of paper some of the still wet powder that had remained enclosed: in three minutes it grew hot and smoked. I put the surplus in a jam glass on the stand (§. XXI, let. b ) , & I covered it with a small matrass. The water rose there little by little, and in three hours it occupied almost a third of it. The water stopped at this point: so I took off this matrass, I filled it with new air, and I replaced it on this ferruginous mixture. The water came up there.
The Air absorbing itself here so readily, it is not surprising that the heat was so sensitive to the touch.
I hope I have demonstrated that heat is composed of two constant parts; namely, of the inflammable principle & of the Air of Fire which is found in the atmospheric air. A man of common sense will doubtless not conclude from this that these two constituent substances must always begin to unite for heat to be formed, it exists partly fully formed in the pores of bodies, and we will mention it later in this book.

§. LV.
Properties of heat.
We know that a concave metal mirror reflects the heat of very hot coals placed in its hearth so much that when it is received on a second concave metal mirror, a hearth is formed capable of igniting inflammable substances. Is this phenomenon due to the heat of these burning coals, or to their light alone, or do the heat & the light contribute to it together? Those who confuse these expressions, who attribute the name of Fire to all that has only some relation to it, who give it indiscriminately to light, to heat, to the phlogiston which is contained in all bodies, etc., will not hesitate to answer my question, it is the Fire which is reflected by the mirrors, which is united and concentrated there, and which consequently produces the same effect as the light of the sun.

§. LVI.
[a] That we place ourselves in winter in our apartment in front of a stove, when the wood is well aflame there, and that the stove is heated in such a way that at a distance of ten feet we still feel the heat sufficiently, of which the torrent flows into the bedroom through the door of the stove, which will be left open. We will nevertheless see its breath very distinctly, which does not take place in summer in a much less heated air: whether we carry a light or smoke in this torrent of heat which springs in a straight line from the furnace , not only will the light continue to burn peacefully, but the smoke will rise perpendicularly. [c] As there is a constant current of air from the room into the stove to replace the Air which the heat has expanded, and which has gone up the chimney, why this heat, which springs from the stove into the apartment, is it not in the same way drawn into the pipes of the stove by the current of air? [d] If the Air is strongly agitated in any way from right to left in front of the door of the stove, this will no more change direction in the heat which comes out of the stove than in the rays of the sun, so that in approaching the face of the stove, on the left side, one will feel the wind blowing through the heat, but it will not be not hot. [e] We know well that when the light of the sun traces on a white wall the shadow of a body reddened or only ardent, this shadow is surrounded by a vapor which wavers with a prodigious speed, which one cannot can attribute only to the expansion more or less force which the heat causes in the Air, through which the rays of light break. How does it happen now that, sitting in front of the stove, the window on his right & the white wall on his left, we do not see this flickering shadow on the wall, although the rays of the sun which cross the panes of the windows? cut the current of fiery heat to fall on the white wall, while suspending an iron or a heated hot stone in this same current, this wobbling will be observed in the open air as well as on the white wall? [f] Hold a large pane of glass between the face & the stove; you will indeed see the fire, but you will not feel any heat, the glass will intercept it entirely. [g] The light of this fire can be reflected in the same way by a plane mirror of glass, without this light having the slightest heat: the mirror retains all the heat that strikes it. [h] But a polished metal plate will reflect light & heat without this light having the slightest heat: the mirror retains all the heat that strikes it. [h] But a polished metal plate will reflect light & heat without this light having the slightest heat: the mirror retains all the heat that strikes it. [h] But a polished metal plate will reflect light & heat, following the same laws as sunlight. Since the heat is also reflected, it is not surprising that this plate does not heat up. [i] It is for this reason that with a small burning mirror one can produce, at two ells distance from the furnace, a hearth in which the sulfur is ignited. It can be held for a very long time in this position without it overheating: but if it is coated with a little soot by passing it over a lighted candle, it cannot be kept for four minutes in the same position in front of it. the stove without burning your fingers, [k] By reflecting the heat which rises from the stove to another place by a plate of polished metal, we produce a sensible hearth, but only up to the distance of two to three ells of the plate. the light, without one feeling the slightest heat in this hearth.
[l] By placing a pane of glass between oneself and the fire, one can likewise form behind this glass a clear point with the concave mirror, but it will be devoid of heat. It is for the same reason that one can in truth form in front of this fire clear points with burning glasses, but which do not have the slightest heat, [m] The concave mirror of metal and the plate heat up however very quickly as soon as they touch a hot body, although the heat which springs from the stove does not communicate heat to them. For example, if one closes the upper key of the stove, the very hot air immediately rises from the mouth. Whether one holds the concave mirror or the metal plate in this perpendicularly rising heat, the metal will soon be heated. This heat cannot be reflected.

§. LVII.
Whence it follows that the heat which rises in the stove with the Air, and which flies up the chimney, is really different from that which rushes through the door of the stove into the room. This moves away in a straight line from the place of its birth: the polished metals reflect it under an angle equal to that of incidence (§. LVI, let. H, i ). It does not combine with Air: hence its original direction cannot be changed by a current of air (let. c , d ), and the vapors that the mouth exhales are visible in the chamber (let. . To). They are not so in summer, because the air is really combined in this season with the heat, and warm air is always capable of holding more water in solution than cold air. The Air therefore not combining with this heat, it is plausible that it is not dilated by it, which explains why it does not cause any flickering to be seen when the light of the sun passes through it (let. e ) . Although these properties are those of light, I do not think that one wants to attribute these phenomena to the light of the flame, much too weak in comparison with that of the sun, & the effect of inflammation ( let . i ) is much greater when the wood is consumed & converted into clear burning coals, though the light is much less. Moreover, one can separate this light from the heat by means of a glass mirror (let . g ): because, in this case, the heat remaining in this glass, the reflected light does not make one feel hot. The same thing is seen from the letter g to l. The ardor that rushes through the mouth of the furnace has therefore some relation with light, but it is not yet quite light; because a glass surface does not reflect it like metal surfaces (very remarkable circumstance). It also acts at a much shorter distance from the place of its origin, at least judging by touch: it soon converts into heat when it unites with a body, let . g ) & to the metal mirror coated with soot ( let . i ), &c: then it can be transmitted from one body to another, combine with the Air, & produce flickering there ( let . e ) . All this does not belong only to the ardor which rises through the mouth of the stove in the apartment, but also to each fire. Imagine a little mound of burning coals: the ardor which shoots up outside, all around this mound, is the same as that which allows itself to be reflected by the metallic plate, but that which rises in the air. 'Air & that the wind agitates, is that which has combined with the Air. I will call the first, to distinguish it,

§ LVIII.
Whence, then, comes this remarkable difference between the radiant ardor & the heat ? Would the first not have encountered, at the time of its formation, enough air matter to which it could attach itself, or would it have obtained, at the beginning of its existence, such a strong elasticity that the 'Air & polished metals cannot retain it in the velocity of its course? The first conjecture does not seem to me to be justified: for if the radiant ardor could not combine with the Air, for lack of finding any, why does it not unite with it when it encounters it, and why does it soar through the Air, like the rays of light? I am justified in believing the last of these conjectures very probable. But who can communicate this great elasticity to heat? I think that the Air of Fire is capable of combining with more or less phlogiston, and in this case it must produce phenomena proportionate to the quantity of phlogiston united to it. Do we not know that a great number of Bodies which combine with the inflammable principle are capable of receiving it in more or less considerable proportions? Do they not thereby acquire more or less volatility & elasticity (15), as I have already advanced (§. XXVII), & as the spirit of Nitre clearly proves to us? The Air of Fire must therefore be endowed with a similar property. This air and the phlogiston being the true constituent parts of heat, & the heat being very likely to combine with more phlogiston, as I will prove it in the continuation, this increase in elasticity, communicated by the phlogiston of the heat, decreases by the influence of the attractive virtue, in such a way that the metals, as well as Air, are afterwards able to attract it. I believe we we are now in a position to answer the question of §. LV. It is the radiant ardor which produces the inflammation in question. This substance is invisible & distinct from Fire.

§. LIX.
Light.
I have shown until now, by unequivocal experiments, the constituent parts of heat & the next principles of Air, as much as it was necessary for me for the explanation that I propose to give of Fire. : but as we cannot admit fire without light, we must still consider this surprising appearance before we can arrive at a solid theory of Fire.
There is no doubt that the light of the sun and that of burning fires are the same thing; it affects the eyes like that of the sun, & makes us see, through the prism, the same sorts of colors; but as it is infinitely weaker, it is not surprising that the rays, concentrated by the burning glass, do not produce a fire.
It is no less certain that light should be placed in the rank of bodies like heat: but I am all the less inclined to believe that light and heat are only one and the same thing, than the contrary. seems to me proven by experiments. The sequel will clarify this proposition.

Proofs of the presence of the inflammable principle in Light.

§. LX.
If a solution of silver in nitrous acid is exposed to sunlight on a piece of chalk, the solution blackens. Sunlight, reflected by a white wall, produces the same effect, but more slowly. Heat without light produces no change in this mixture. Could this black color be real silver? We will only decide this question after having demonstrated the presence of phlogiston in the light.

§. LXI.
First experience.
I put a little silver clay on a small piece of porcelain, and exposed it to the hearth of a burning glass: immediately the surface of this clay became silver again. I mean by silver ground, the silver which has been dissolved in a pure nitrous acid, and precipitated pure the alkali of tartar. It is certain that nitrous acid removes phlogiston from perfect metals as well as from imperfect metals (§.XXVII, b ), which is sufficiently proved by the effervescence of these solutions and the redness of the vapors which are exhaled from them. These metallic precipitates are indeed soluble in pure nitrous acid, but it does not impart to them the most slight redness. So it is with the land of silver. The silver, reduced to the focus of the burning glass, colors the vapors of the nitrous acid red during its dissolution. From where would this money have taken phlogiston, if not sunlight?

§. LXXI.
Second Experience.
[a] I put a little lime of mercury obtained from nitrous acid, or in other words from the red precipitate, on a ducat: I placed it at the hearth of a burning mirror, the powder began to smoke, and the gold bleach.
[ b ] I dissolved gold in aqua regia prepared with aquafortis & sea salt, & I precipitated it with the alkali of tartar. I placed this gold clay, well dried and watered down, on a piece of porcelain, in the hearth: it became dark brown, and took on the properties of real gold.
One could attribute this reduction to the heat of the hearth, but that itself would demonstrate the presence of phlogiston in the light, since there can be no heat without phlogiston. Moreover, there are several proofs contrary to this opinion.
[c] I poured a little of the purest fuming nitrous acid (§. XXV) into a vial closed with a crystal stopper, & I exposed it to the light of the sun. Within three hours I found the vial full of red fumes. The heat of the earthenware furnace produces the same effect on this acid; but it takes four weeks for the redness to become noticeable.

§. LXIII.
Third Experience.
I precipitated a solution of silver with sal ammoniac, sweetened it & dried the precipitate, & I exposed it, for fifteen days, to the rays of the sun, on a piece of paper. As soon as the surface of my powder darkened, I turned it over. I repeated this maneuver frequently, then I poured on this powder, which seemed black, the spirit of caustic sal ammoniac, and I put it in digestion. This menstruation having dissolved a great part of the horny moon, there remained a subtle black powder, which, watered down, was almost entirely dissolved in its turn by pure nitrous acid, which it rendered volatile. This solution was again precipitated into the horny moon by sal ammoniac: thus the black which the light gives to the horny moon is reduced silver. It is therefore the same with the silver solution spread on chalk (§. LX). I wrapped some white horny moon in paper, and exposed it for two whole months to the heat of a furnace, without its color changing.
Silver being unable to combine in the metallic form with marine acid, it is necessary that in the above reduction as much marine acid of the horny moon must be separated as there are particles of its surface converted. in silver.
[b] To make sure of this, I poured on horny silver, well watered down, distilled water which rose but little above the powder; I put half of it in a crystal glass, which I exposed to the rays of the sun, and which I turned over several times a day: I left the other half in a dark place. Fifteen days later, I filtered the water that covered the horny moon exposed to the sun, which had turned black. I poured this water, drop by drop, into a solution of silver, which was again precipitated into a horny moon. The water that was on the other portion of the horny moon produced no effect on the silver solution, & the white color of the horny silver had not varied, [c] I poured in etching on the horny moon, THE §. LXII, let. c , actually see the reason.

§ LXIV.
Fourth Experiment.
I evaporated a solution of gold to dryness, & I redissolved the residue in distilled water, which I poured into a vial of white crystal: I closed this vial with a glass stopper, & I exposed it to the sunshine. In fifteen days I discovered (especially when I looked at this solution in the light of the sun); I discovered, I say, in this solution a large quantity of small flakes of gold, and its surface was coated with a small, very fine film of gold. I had started by evaporating the gold solution, so that the superabundant acid would separate from it, it could have put, in some way, an obstacle to the reduction. I will relate only one more experiment, to complete to convince us of the presence of phlogiston in the light. Pure etching does not dissolve manganese, unless phlogiston is added to it, like sugar, for example: then the solution becomes clear like water, and colorless. By pouring into this solution the alkali of tartar, we obtain a white precipitate, which is nothing else than manganese united to the phlogiston of sugar. If the phlogiston be separated from it in any way, the manganese reappears under the black color which is natural to it (see the Memoirs of the Royal Swedish Academy of Sciences, 1774). The quickest expedient to separate the phlogiston from it is to spread the manganese, clearly sown, on a sheet of tin placed on hot coals; it promptly resumes the color black. This manganese, however divided it may be, does not dissolve in nitrous acid without phlogiston. It will be the subject of §. following.

§. LXV.
Fifth Experiment,
I poured about half an ounce of pure fuming nitrous acid into a crystal vial, seven-eighths of which remained empty: I put the manganese in question there; I closed the vial with a crystal stopper, and I exposed it for two hours to the light of the sun. In this interval, the mixture had clarified & had lost its black color. I opened a little more of the same manganese, I corked the glass again, and exposed it again to the rays of the sun. In a few hours the manganese was also dissolved. I repeated this operation until the acid refused to receive any more: then I poured in six times as much distilled water. I filtered the solution, & I precipitated it with the alkali of tartar: I washed this white precipitate well, & dried it at a gentle heat, it was manganese united to phlogiston with aerial acid of alkali. To convince yourself of this, dissolve this precipitate in vitriolic acid, and distill in a small retort over a high heat; the manganese, contained in the residue, will resume its natural color, and the acid which has passed into the container will have all the properties of volatile sulphurous acid. One can also mix one part of powdered saltpeter with four parts of this white manganese: put this mixture in a small retort & distill it; it will blacken very quickly, and the saltpetre will be alkalized. Another way of proceeding can also be used. Fill a small vial with this phlogisticated manganese; put a cap of chalk in it, and place it in a sand bath in a crucible: redden the vial for a quarter of an hour; take it out of the sand while it is a little warm; pour the still white manganese onto a piece of paper, it will ignite immediately, and will be converted into a black powder. You can also leave the flask to cool completely, & throw the manganese on a hot plate, but red dot, the manganese will begin to redden, & will resume its first shape.
I first made the white manganese redden in a closed vessel to be able to obtain this inflammation, because by putting it on a hot iron before having roasted it in a closed vessel, it would be well calcined: but its inflammation would be scarcely visible, on account of the aerial acid with which it is combined, for this passes into the Air as the phlogiston separates from the manganese; & a single part of aerial acid, mixed with eight to ten parts of common Air, extinguishing the Fire (§. XXII), it is necessary to expel this acid from the manganese in closed vessels, In this experiment, the phlogiston drawn from the sun's rays ignites.

Light is not a simple substance or an element (16).

§. LXVI.
If light were a simple matter, the preceding experiments, and several other experiments already known, would force us to conclude that it is nothing other than the inflammable principle: but having demonstrated that the phlogiston forms the ardor & heat by its combination with the Air of Fire, & our atmosphere being provided with a large quantity of this Air of Fire, the phlogiston which flows continuously from the sun, combining with this Air of Fire, should not produce only heat: then we would exist in a thick darkness. However, light, however concentrated, produces no heat in the Air. I cannot therefore convince myself that light is only pure phlogiston: moreover, my experiments would not allow me to do so. If that were so, the nitre would have to be alkalized at the focus of the fiery mirror, and the limes of the imperfect metals would have to be reduced there, which does not happen. One could object to the truth that the Air, by means of the heat of the hearth, calcines these limes as they are reduced. It is therefore only a question of making this experiment in an air which is no longer susceptible of receiving phlogiston, that is to say, in a corrupted air. M. Lavoisier and others have already responded to this objection. He calcined metals with burning glass under a bell jar, he could only deprive them of their phlogiston in a certain portion of air, that is to say, that the phlogiston could not separate metals, only in proportion to the Air of the Fire which was under the bell. The remaining air under the bell was spoiled air. If the objection were valid, why did M. Lavoisier, continuing his calcination, Was he not able to restore the metallic form to these limes and by not being able to remove from them the phlogiston which the light would have furnished them? I may also be told that if light were not such a subtle and pure phlogiston, it would surely reduce the lime of imperfect metals, of which phlogiston is coarse, as well as that of perfect metals: but phlogiston is a in all bodies it differs in no way. That of gold and silver is the same as that of iron and oil: moreover, imperfect metals reduce perfect metals. For example, copper makes the lime metallic form of silver & of which the phlogiston is coarse, as well as that of the perfect metals: but the phlogiston is one in all bodies, it does not differ in anything. That of gold and silver is the same as that of iron and oil: moreover, imperfect metals reduce perfect metals. For example, copper makes the lime metallic form of silver & of which the phlogiston is coarse, as well as that of the perfect metals: but the phlogiston is one in all bodies, it does not differ in anything. That of gold and silver is the same as that of iron and oil: moreover, imperfect metals reduce perfect metals. For example, copper makes the lime metallic form of silver & of mercury dissolved in nitrous acid, &c. One could reply to this that in this experiment the phlogiston decomposes; that the subtle part (which is the same as that which penetrates through the retorts, and which reduces the lime of imperfect metals) attaches itself to the silver lime. But then I would ask what is this coarse part of the phlogiston which has remained in the copper solution. Would something material be separated from this pure phlogiston which has united with silver? (M. Baumé believes that it is vitrifiable earth). It would be necessary in this case that by evaporating to dryness, & distilling this solution of copper in a retort at a violent fire, the copper earth which would be found in the residue of this distillation, after the nitrous acid had been separated from it, was reduced only by the red ardor : for the subtle earth with which the phlogiston would have been combined should still exist in the residue, & be able to very easily combine again with the pure phlogiston which penetrates the retort. Experience has shown me that this does not happen. We thus see that all these opinions come from the fact that we did not know what makes up heat, which we only regarded as a subtle phlogiston.
The beautiful colors from which the light constantly shines, are further proof that it is not simply phlogiston. The affinities of light and phlogiston which make them act so differently on bodies, give us enough to know that they cannot be of the same nature. The following experience further adds to the strength of this opinion. Make fall on the floor the rays of the sun decomposed by a prism placed at the window, & put in this colored light a paper on which we will have dispersed some horny moon: you will observe that exposed to violet rays, it will blacken much more quickly. than in the other rays, that is to say, the silver lime more readily separates the phlogiston from the violet light than from the other rays (17).
I demonstrated the presence of phlogiston in light, and I showed that it was not simply phlogiston: thus light cannot be considered as a simple substance.

When the movement of Light is not interrupted, it causes neither ardor nor heat.

§. LXVII.
By exposing to the rays of the sun two equal thermometers, one of which is filled with dark red colored spirits of wine, and the other of non-coloured spirits of wine, the red liquor will rise much faster than white. But, if you put these two thermometers in hot water, their liquors will rise at the same time. The nearer the color of a body approaches black, the more quickly it is heated by the rays of the sun; the whiter it is, the longer it takes for the sun to heat up. The cause of this phenomenon is found in the more or less affinity that bodies have with light. Hence it is that those which repel light in all directions, and which are called white, heat up only slightly. & very slowly. It is the same with those which do not oppose the passage of the rays of light, and which are called transparent. The heat which the rays of the sun cause us, therefore, comes absolutely only from the fact that their movement, whose velocity is extreme, is stopped by certain bodies.
Let us see then if this heat is peculiar to the rays of the sun, or if it owes its origin to these bodies.

§. LXXIII.
I have shown, in §. precedents, that the radiant ardor (§. LVII) adhered neither to the Air, nor to polished metals, but, that with a mirror of concave metal, it produced a hearth likely to ignite the bodies, that when 'it was once united with other bodies, it could then combine easily with the Air & the metals. These properties are common to it with light. I demonstrated at the same time that this blazing property of radiant ardour, should not be attributed to the light with which it was combined (§. LVII), & that it produced this effect only after having been attracted by other bodies. Wouldn't it be the same with the rays of the sun? I suppose that the heat which most bodies obtain from the rays of the sun, is the same as that which is interposed in the pores of bodies, and which is set in motion by the friction occasioned by the light of the sun (for the we want the heat to always come from friction). Air, considered in its state of purity, which is not easily heated by the rays of the sun, is heated when it surrounds a body on which the light of the sun has darted for a short time, which is the main cause of the heat that the Air makes us feel in summer. This supposed, this body must lose its natural quantity of heat. If so, the loss must have been considerable, when the sun has been shining on him almost every day of the summer. Nevertheless I find that a piece of iron, for example, which one bends in all directions on itself, or which one exposes to the light of the sun, heats up as much in autumn as in spring. One could make a specious objection against my reasoning, by telling me that the body on which the sun shines, having lost its heat during the day, can withdraw it from the Air & from the surrounding bodies after sunset, & that this could well be one of the reasons why the evenings & nights are chilly. It was to answer this objection that I made the following experiment. I suspended, on June 22, a black lead plate in the open air, so that the sun could shine on it all day. The plate was constantly so hot that a delicate hand could not hold it for long. Two hours before sunset, I rolled up the plate & put it in a beer glass filled with water, I put another beer glass beside it, also full of water: I put a thermometer in each of these glasses . The liquor of the one who was in the same glass as the roll of lead immediately rose a little, because of the heat of this roll. Two hours later, the heat was equal in the two glasses. I watched all night the height of the liqueurs. As one fell, the other fell likewise. However, if the above objection were correct, the water in which the lead roller was should have lost a greater amount of heat. I am therefore very inclined to believe that the light of the sun does not manifest any heat, as long as its rectilinear movement encounters no obstacle. But if it is stopped by the attractive virtue of bodies, its heat becomes sensible like that of radiant ardour.

Constituent parts of the Light.

§. LXIX.
The rays of light being converted into heat when they strike the bodies which attract them, it would appear at first that the light is nothing else than a heat moved with an incredible velocity, because it dilates like the heat the bodies with which it has combined: it communicates to our nerves the same activity as the heat of Fire, and in this state of combination, it is invisible, like heat. It does not blacken the horny moon, does not reduce the precipitate of gold, does not redden nitrous acid, and manganese cannot be dissolved in it. This is precisely the opposite of what I noticed in §. LXII, LXIII & LXV: because, by coating with a thick black color a glass which contains these materials, & by letting the sun's rays act for a few days, the glass heats up, but the substances it contains undergo no change. Thus the light retained by bodies produces the phenomena of heat. It is therefore more than probable that light is composed of the same principles as heat.

But light being still endowed with other properties than heat and radiant heat when it can continue its course freely, one has the right to think that it is not simply heat, or at least that the proportions of its constituent parts are different from those of ardor and heat .

Enlightened chemists know that there are a large number of bodies capable of admitting more or less phlogiston into their combination, whose properties vary according to the proportion of phlogiston they have received. I have already mentioned it (§. XXVII), and the oil of vitriol also confirms this fact for us. Why should this not be applicable to heat, being shown that it is a matter composed of phlogiston & Air of Fire. When this Air has taken hold of a little more of the inflammable principle than is necessary to produce heat, radiant ardor results. 've observed in the radiant ardor increases , light is formed; yes, no doubt, the superb brilliance of the different colors or of the different kinds of light, depends only on an aroma of more or less phlogiston, it is the violet & purple light which contains the least phlogiston, because the prism has more affinity with it than with other kinds of light. This reason is all the more well founded, as the radiant ardor (§. LVII), which certainly contains less phlogiston than light, is also attracted to glass, but even more strongly.

Here is why the eye can fix violet rays longer than red rays: in red rays each particle of light is combined with a little more phlogiston, so this light, however subtle, must be composed of molecules larger than violet light, & thereby produce more effect on our optic nerves. The violet rays reduce corneal silver more rapidly than the others (LXVI). It seems that being more strongly attracted by the prisms, their movement is slowed down; which gives the silver earth more time to exert its attraction, by means of which it decomposes the violet light.
I therefore believe that each molecule of light is nothing else than an atom of Air of Fire combined with a little more phlogiston than such a molecule of heat.

§. LXX.
The experiments reported at the beginning of §. above, lead me to ask why light manifests quite different properties after it has been attracted by bodies, and after this adhesion it has acquired the principal qualities of heat. The answer would be easy, if I could demonstrate that all bodies are capable of absorbing the superabundant phlogiston of light: but there are few which have this virtue, and supposing that it were, all bodies struck during some time from the rays of the sun, experienced some considerable changes, which does not happen. It is equally difficult to explain why the radiant ardor (§. LVII) is converted into heat by the bodies which attract it. The chemical affinities which produce the most surprising changes in bodies act only when the bodies are in contact at all their points. Heat, as matter, cannot penetrate a body: it is only interposed in its pores, it then touches the matter of the body only at a small number of points. If the heat is increased, it touches it in many more parts, but it is more condensed there. Then if the body has, by nature, more affinity with the phlogiston than the Air of the Fire, the heat is destroyed: it is what happens in the reduction of the limes of perfect metals by the simple ardent heat, which takes place only when these limes redden, or when they are ready to redden.

Fire.

I now come to the goal towards which all previous experiences have been directed. I know how to appreciate the infinite usefulness that the theory of Fire must be to a man who seeks to acquire exact knowledge of the properties and constituent parts of all bodies. Experiments, intended to serve as a basis and interpretation for so many other effects, must be carried out with the greatest care, to avoid erroneous systems which cannot fail to throw us into the vagueness of uncertainties. Chemists, who almost always operate with the help of Fire, are the only ones in a position to undertake such experiments. Only they can guarantee them, but it is necessary that they have received enough courage from Nature not to be discouraged by the innumerable difficulties presented by research on fire. We are frightened by reflecting on the centuries that have passed, without having managed to acquire more knowledge about its true properties.

However, those who wish to know the phenomena of Nature should not allow themselves to be stopped by the obstacles they encounter on their way. Some people fall into an absolutely contrary fault, by explaining the nature & the phenomena of Fire with so much facility, that it would seem that all the difficulties are removed. But what objections can we make to them? Sometimes the heat is Fire, sometimes the light is Fire, soon the heat is elemental Fire, soon it is an effect of Fire: there, the light is the purest Fire & an element, there, it is already diffused in the entire expanse of the globe, and the impulse of Elemental Fire communicates to it its direct movement, here, , & which is delivered by the expansion of this supposed acid, &c.

It is therefore very important to make new experiments, to get us out of this labyrinth: but, before going into the subject, I must explain what I really mean by the word phlogiston.

§. LXXII.
From Phlogiston.

1°; Phlogiston is a real element (18), a perfectly simple principle (*). (*) Many physicists believe that it is a combination of elemental fire (the name they give to heat) with a subtle earth, which, according to M. Baumé, is vitrifiable earth, and which he regards as primordial . When this earth is exposed to Fire, the heat separates from it & spreads it in the Air. Does this elemental Fire combine with the Air, or is it only scattered there? Why can't we make phlogiston with heat & vitrifiable earth (19); Mr. Baumé claims that the residue charcoal of distilled oils is almost pure phlogiston. When this delicate charcoal is consumed, very little soil remains. It is inconceivable that such a small amount of earth could absorb so much heat or Elemental Fire. What is lost in the combustion is the weight of the heat: but does the aerial acid, which is released so abundantly from this coal during its combustion, weigh nothing?

2°. It can, by its affinity with certain matters, be transmitted from one body to another: then these bodies undergo considerable changes, so that with the aid of the heat which is interposed therein, they frequently become susceptible of fusing, or being converted into static vapours, & in this connection it may be regarded as the chief cause of the odor.

3°. Very often he arranges the particles of bodies in such a way that they attract either all the rays of light, or only certain rays, or even none.

4°. In passing from one body to another, it communicates to it neither light nor heat.

5°. It contracts with the Air of Fire such a subtle union that it very easily penetrates the finest pores of all bodies. This union forms the matter of light and heat. In all these combinations, the phlogiston does not undergo the slightest change, it can still be removed from this last combination. It is impossible to obtain it alone, for it separates itself from no body, however weakly it clings to it, if it does not find another with which it can be in immediate contact.

§. LXXIII.
Flammable Bodies.

Bodies called inflammable are either hard or soft and fluid. Among the latter are sulphur, fossil coal, zinc, yellow amber, wax, camphor, oils, spirits of wine, &c. Phlogiston is very abundant in these substances; but he does not necessarily adhere to them. A multitude of experiments seems to demonstrate that the acid principle is the matter destined to contract a more or less strong union with the phlogiston. The objection that could be made on this subject with regard to metallic earths does not seem to me of any importance.

I see that the arsenical acid acquires, with a little phlogiston, the aspect of an earth, & with a greater quantity, the form of a regulus (§.XLI). What would we say, if I thought that all metallic earths, & even in general all the earths, are only various kinds of acids? Water is the main earth made fluid by heat, it is this which fixes the acids, although these two substances are both volatile. Phosphoric acid is volatile: as we see, when phosphorus is allowed to burn in a stoppered flask, the acid attaches itself to the walls on all sides, and allows itself to be sublimated from one side to the other by a candle. lit: but if water is added to it, this acid supports the red heat without evaporating.

Fuming vitriolic acid, fuming nitrous and marine acids, and even concentrated vinegar, are made fixed by water. We know, up to now, only one acid which is so fixed by aqueous vapors, that it deserves the name of an earth, it is fluorspathic acid: it is this which forms, with the aqueous vapours, the vitrifiable earth, an earth which Chemistry has not yet succeeded in reducing to its constituent parts, the same applies to other lands.

The property which metallic earths have of attracting phlogiston must depend solely on the substance of their acids. Vitriolic, nitrous and phosphoric acids strongly attract it; marine and spathic acids scarcely attract it perceptibly: hence vitrifiable earth has no affinity with phlogiston. The combination contracted by most earths with acids depends only on a little phlogiston with which these acids or these earths are intimately united. It is manganese that gives me reason to draw this conjecture, it has a lot to do with vitrifiable earth; it is insoluble in acids: but, if phlogiston is added to it, it obtains all the properties of an absorbent earth (§. LXIV).

If we could separate, in a suitable way, from the metallic and absorbent earths, the phlogiston which adheres to them so strongly, it is probable that they would manifest their acid nature. What a vast field for new & brilliant experiences! But I realize that I am moving away from my goal. If we could separate, in a suitable way, from the metallic and absorbent earths, the phlogiston which adheres to them so strongly, it is probable that they would manifest their acid nature. What a vast field for new & brilliant experiences! But I realize that I am moving away from my goal. If we could separate, in a suitable way, from the metallic and absorbent earths, the phlogiston which adheres to them so strongly, it is probable that they would manifest their acid nature. What a vast field for new & brilliant experiences! But I realize that I am moving away from my goal.

§. LXXIV.

We know oily mixtures quite well: we know what are the constituent parts of sulfur & phosphorus: & although it is very difficult for the Art to imitate vegetable & animal oils, we nevertheless have their constituent parts before our eyes. . If we are willing to reflect on it, we will soon see the great difficulty there is in composing oils by the means used in chemistry. When we have completely destroyed the oils, we find only phlogiston, aerial acid and water.

However, it is believed that they contain an acid resembling vinegar: a small quantity can even be obtained by distillation. But, this acid being also liable to be destroyed & converted in the same way into water, in aerial acid and in phlogiston, it is possible that it is only a product of distillation, formed by the union of these three substances. Until now no one has yet succeeded in composing oils with phlogiston and vegetable acids, and there is no reason to consider this compound acid as a constituent principle of oils. Why then, being able to make sulphur, should we not be able to compose oils in the same way? If we want to combine phlogiston with aerial acid, we must and there is no reason to regard this compound acid as a constituent principle of oils. Why then, being able to make sulphur, should we not be able to compose oils in the same way?

If we want to combine phlogiston with aerial acid, we must and there is no reason to regard this compound acid as a constituent principle of oils. Why then, being able to make sulphur, should we not be able to compose oils in the same way? If we want to combine phlogiston with aerial acid, we must use a substance that contains phlogiston. If we wanted to choose one that had more affinity with it than aerial acid, we would be very clumsy. The phosphoric, vitriolic and nitrous acids, the metallic earths and the Air of Fire, decompose all the coals and the oils, and in the latter, the phlogiston is combined with the aerial acid. The more or less earth contained in oily substances must be regarded as accidental: earth is as little necessary there as for sulfur and phosphorus. How difficult must this composition not be? It is contraindicated that the constituent parts of the oils are phlogiston, aerial acid & water.

§. LXXV.
Fire.

Fire is that state in which the Air places certain bodies when they have received a certain degree of ardor, by means of which they communicate more or less heat, spread more or less light, are reduced to their constituent parts, & totally destroyed, constantly causing the loss of a considerable portion of Air.

First Observation.

It follows from this definition that the red heat of stones, earth, salts, etc., cannot be called Fire, because it produces no changes in the Air other than expansion, and it does not not even the help of Air is needed to make these substances blush.

Second Observation.

The name of Fire therefore does not suit either ardor or heat; for there are many ways to produce it without the assistance of the Air. It is the same with sulfur liver, some linseed oils, oil varnish, iron filings, &c.
These give birth to the truth of the heat by the assistance of the Air, & it also loses a part of Air (§. LI). But, as there is a lack of light, the name Fire cannot be used.

Third Observation.

The light of certain species of stones, when they had been heated, the phosphorus of Bologna, that of Balduin, the electric light and the light of the sun, should not equally be taken for Fire: they do not cause any change to Air, & their effect takes place in a vacuum. On the contrary, the phosphorus of the urine is a true Fire, it illuminates, it is hot, it destroys & it absorbs the Air: none of its properties can manifest itself in corrupted Air. We are therefore expressing ourselves badly when we say that water is composed of molecules of ice and fire. It is the same with these expressions: The Fire enclosed in bodies , the Fire of the sun , &c .

§. LXXVI.

I would now like to submit my theory on the formation of Fire, and the phenomena it manifests to us, to the judgment of my Readers. It is deduced from the experiences I have reported so far.

1°. Every inflammable body must acquire a certain quantity of heat before acquiring the igneous movement (*).

(*) Heat being an infinitely subtle & elastic fluid, it penetrates the interstices of inflammable bodies, & breaks their aggregation (the oils are then converted into smoke); which gives the Air the means of touching them at a greater number of points: the result is the beginning of their destruction. The weaker the union of the constituent parts, the less heat is required to excite the inflammation, only very little is required for phosphorus. I cut about a bulk of phosphorus into small pieces, to see if the light from this body did indeed produce more heat than that of Air.

I placed the ball of a thermometer in the middle of these pieces: the liquor began to rise, and in a quarter of an hour the phosphorus ignited, although a piece of phosphorus does not ignite by itself. It is therefore necessary that the number of surfaces supply the air of Fire with a greater quantity of phlogiston, and that more heat result from it, which makes the explanation of this inflammation easy. The volatile vitriolic ether ignites, holding above it a red-hot iron. It is the same with flammable air which vitriolic acid releases from iron or zinc. Sulfur requires less heat than fatty oils. The water that the Air contains is the main cause of the inflammation of phosphorus which will be discussed below.

2°. Then this body is in a condition to let its inflammable principle escape, provided only that there is a matter there which has more affinity with phlogiston than it (*).

(*) If phlogiston is combined with aerial acid, it can be removed by phosphoric, nitrous, and arsenical acids, by metallic earths, &c; but in this case neither ardor nor light is formed .

5°. If the body heats up in the open Air, the Air of Fire, which is part of the Air, exerts a stronger attraction (*).

(*) I have demonstrated, in different places in this Treatise, the great affinity of the Air of Fire with phlogiston.

4°. Immediately the flammable principle comes to light, breaks its irons, and combines with this Air of Fire (**).

(**) It is therefore necessary for phlogiston to abandon aerial acid, when it is oils or carbons which undergo this change, vitriolic acid, when it is sulphur, urinary acid, when it is is phosphorus, and the metallic earths, when they are metals: but it is rare for phlogiston to abandon them completely. Vitriolic acid still retains enough to produce the volatile sulfurous acid. The arsenical acid retains, after the regulus is consumed, as much as it takes to be arsenic. Is it therefore astonishing that arsenical acid decomposes heat, and becomes arsenic (§. XLI)? Could it be doubted that heat cannot convert vitriolic acid into volatile sulphurous acid? The metallic limes certainly also retain some portion of phlogiston.

5°. It is from this combination that the heat is formed which adheres to the corrupted air, dilates it & obliges it to rise according to the hydrostatic laws (***).

(***) It adheres to the corrupted Air (§. LVI, m ), because all the air of Fire which was mixed with this Air, has combined with the phlogiston. If one collects the Air which passes over hot coals, a light will soon be extinguished there. However, ardor or heat are not always instantaneously composed by the union of these two constituent parts; there is a portion of it which pre-exists in most bodies, if not in all. We cannot be persuaded that oily mixtures contain all the heat that we feel when they burn. The bodies contain only this heat which can manifest itself without the help of the Air: it exists there in two ways. Sometimes it fills the subtle interstices of the bodies into which it has entered, so to speak, as in the most delicate capillary tubes; sometimes it is combined with certain bodies, and forms one of their constituent parts, which we will mention later. The heat interposed in the pores has no perceptible effect, because the attraction of matter opposes its elasticity. the more so as all the experiments seem to demonstrate that all the effects of heat on bodies are due to dilation. There are two ways of releasing the bodies from this heat which they contain, either by tightening their pores even more, which is obtained by rubbing one body against the other, by bending it, or by hammering it (do not shouldn't the heat be released when you bend & fold a metal in all directions, since you open its pores on one side by compressing those on the opposite side?); or by separating the integral parts of the bodies, which takes place partly by fermentation, rotting & chemical solutions.

6°. No sooner has this heat been produced than the inflammable body is even more dilated than at the beginning, and its phlogiston is more exposed (*).
(*) The more the heat increases, the more the parts are subtly dissolved. The Air of Fire finds more surface, and thereby comes into contact with more phlogiston.

7°. The Air of Fire then comes into contact with more phlogiston; & in accordance with its nature, it combines with a greater quantity of this principle, & forms radiant ardor ( *).

(*) Do we not see that the combination of vitriolic acid with little phlogiston forms the spirit of sulfur, & with a greater quantity of the inflammable principle, sulfur? Arsenical acid has the same property, as does nitrous acid: metallic earths, manganese, form with little phlogiston a kind of absorbing earth, and with more phlogiston, a regulus. The Air of Fire is subject to the same laws.

8°. At the same instant, the constituent parts of the inflammable body are so drawn apart by the increase of the heat, that the Air of Fire, which rushes there in a continual current, still attracts the phlogiston in greater quantity, and composes this material so superiorly elastic, the light, therefore the colors vary, according to the proportions of its combination (*).

(*) When finally the heat, produced in such great abundance, has pushed the smallest molecules of the oily bodies so far apart that they are no longer likely to admit any more, it is easy to believe that their parts must constituents are separated, which can happen all the more easily, as there is here a matter which is able to attract phlogiston in great quantity. The Air of Fire, which rushes constantly in the form of a torrent, seizes as much phlogiston as is needed to compose the light: but since the phlogiston is not, at all points, in contact perfect with the Air of Fire, because of the acids left by the phlogiston which are mixed with the flame, it is also necessary that this Air of Fire,

All these phenomena, viz., heat, radiant heat & light, are produced so suddenly one after the other, that only the blink of an eye is needed to perceive them & to see disappear, & reproduce heat & light again. The more the Air is compressed, the denser the Air of Fire is: then it touches inflammable bodies at a greater number of points; it produces more heat & light, & consequently, the flammable body must be more quickly reduced to ashes (20): a strong current of Air & the bellows proves it to us. When there is not enough phlogiston in an oily mixture for the Air of Fire to be saturated with it, the light is blue, as seen in the flame of coals, inflammable Air, sulfur & spirit of wine. Certain heterogeneous vapors which are found in the flame, seem to attract certain species of lights. Would the cuprous vapors attract all kinds of rays of light, except the green ones & the mineral alkali, all the rays,

Mr. Meyer and several others believe that light pre-exists in inflammable bodies, and that it shows itself when they are destroyed: but this system is contrary to experiments on light, as well as to subsequent experiments. When I see, for example, that the liver of sulfur destroys itself in the open air without heat, without light, while light, even in its most subtle expansions, is still quite visible in the dark, I have reason to believe that light is an accidental thing in the combustion of sulphur.

I am still quite convinced of this, seeing that the spirit of fuming nitre in digestion with sulphur, dissolves it entirely with effervescence, without its appearing to be light. If this solution is evaporated, the result is concentrated oil of vitriol. Phosphorus itself, treated in this way with fuming nitrous acid, dissolves very easily without heat and without light. The rendering of evaporation is here again pure urinary acid.

§. LXXVII.

As for the ability of certain kinds of stones to shine when they have been rubbed or heated, it seems to me very probable that this light is only composed. There is no doubt that phlogiston resides in the fluor calcareous spar & in several other species. Whether these stones are heated by friction or heat, the phlogiston unites with this heat, and increases its proportion in the Air of Fire; what forms the light. It does not matter whether the Air of Fire attracts at the same time as much phlogiston as is needed to produce light, or whether the heat attracts more phlogiston to compose this elastic matter so subtle.

This explains to us again where it comes from that this light is also seen in a vacuum, and that fluorspar shines in very hot water. If this light pre-existed in these stones, it would have to become visible when they are decomposed. When the heat releases this phlogiston, the light ceases. From this comes that the fluorspar that has been blushed a little & left to cool,

Sustained heat, volatilizing the diamond entirely in closed vessels, would it not combine here with the abundant phlogiston that the diamond must contain, and which it would expel from it in the form of light? This clear light (21), observed during this calcination, supports this opinion.

What seems to me most probable, in relation to the phosphors of Baldouin and Bologna, is that these bodies attract the light of the sun or of fire. I can only seek the reason for this in a certain size of the pores, which the molecules of light penetrate without being strongly attracted by the matter of the bodies. The nitrous acid or sulfur which these bodies contain may contribute to it. The heat, necessarily a little coarser than the light, made so elastic by an increase in phlogiston, penetrates them, as if being more strongly attracted by reason of its greater density, and it expels the light from them. The more heat enters these pores at once, the more quickly the light is expelled from it, and the brighter is the light from the phosphorus. I see here the reason why these slightly heated phosphors do not attract light as long as they remain hot: the light then fills these particular openings, the humidity produces the same effect.

§. LXXVIII.

A stone, placed in Fire, first becomes fiery, then red: thus it attracts Fire, not only heat, but also light. The light which, from the beginning, penetrates the stone at the same time as the heat, is converted into heat by the attractive virtue of the matter of Fire, until all the pores are filled with heat. Then the pores are more dilated, the result is subtle openings into which the light penetrates: it is as if imprinted there, & the material of the stone no longer has the ability to convert it into heat by its attraction, so the light does not It is only very loosely interposed: it can therefore very easily be freed from the stone when it is withdrawn from the Fire, so it happens; but if, by some means, the heat is removed from the stone as soon as it is withdrawn from the Fire, the light is lost much more quickly. If you surround a hot iron with water, it will quickly attract its heat. I suppose that this piece of iron remains red for a quarter of an hour in Air, it will not be so for a minute in water, although water does not attract light much more strongly than Air: The reason is that as soon as the water has drawn the heat from the surface of the iron, this surface can immediately re-attract the light & convert it into heat, as happened at the beginning when iron or stone was placed in the heat. Fire.

§. LXXIX.

Nothing is better known than the sparks that steel pulls hard stones, but nothing is more ignored than the cause of this phenomenon. I will show later, by experiments, that the pores of iron are penetrated by a great quantity of heat. Thus, when by a hard & sharp stone one quickly detaches a particle of steel, the interposed heat comes out & adheres in part to the detached molecule: the phlogiston, very abundant in iron, finds itself by this means in a state of combining with a body which has more affinity with it than the earth of iron, it meets the Air of Fire, which increases the heat so much that a greater part of phlogiston is released from it, and from it results the light ; in a word, the steel molecule ignites, all these appearances follow one another in the blink of an eye.

If one of these sparks falls on a loose body which catches fire easily, it heats the point on which it falls; it disengages the phlogiston which finds itself attracted by the Air of the Fire, and the body ignites (22). If this piece of red steel is a little larger, the heat, still enclosed in its center, is dilated by the external heat, & the resistance of such a small piece of iron having to be very weak, it is discarded & divided into even smaller sparks; these are the little sideways sparks that are so often noticed when striking the lighter. I say that this molecule of steel must be detached very quickly. It is easy to think that when the operation is slower, the heat which leaves the pores is immediately re-attracted by the stone & by the whole piece of steel, as being bodies whose density greatly exceeds that of Air. Thus the phlogiston could not be released enough for it to be able to combine with the Air of Fire.

§. LXXX.

I had long desired to have a little haste per se, to see if in its reduction it would also give the air of Fire: my friend Doctor Gahn gave it to me. This supposed precipitate looked like small crystals of cinnabar, dark red. Knowing that mercury cannot be dissolved by marine acid until it has lost its phlogiston, as in its dissolution by nitrous or vitriolic acid, and that this is what makes it necessary to put nitre in a mixture of calcined vitriol, common salt & mercury, I poured marine acid on part of this red precipitate; the solution was soon made & warmed up a little.

I evaporated it to dryness, and increased the heat. Everything sublimated, and a veritable corrosive sublimate was formed. Thus this mercury, precipitated by heat alone, is nothing but calcined mercury. I put another portion of this precipitate on the Fire, in a small glass retort, to the neck of which I had attached an empty bladder. As soon as the retort began to redden, the bladder dilated, and the reduced mercury immediately rose in the cervix. No red sublimate arose, as happens with mercury lime which is prepared with nitrous acid. The resulting Air was pure Fire Air.

It is a particular circumstance that the Air of Fire, which had first removed the phlogiston from mercury during a slow calcination, restores it to it as soon as this lime begins to redden: but we have several facts of this nature, where heat changes the affinities of bodies with one another. As soon as the retort began to redden, the bladder dilated, and the reduced mercury immediately rose in the cervix. No red sublimate arose, as happens with mercury lime which is prepared with nitrous acid. The resulting Air was pure Fire Air.

It is a particular circumstance that the Air of Fire, which had first removed the phlogiston from mercury during a slow calcination, restores it to it as soon as this lime begins to redden: but we have several facts of this nature, where heat changes the affinities of bodies with one another. As soon as the retort began to redden, the bladder dilated, and the reduced mercury immediately rose in the cervix. No red sublimate arose, as happens with mercury lime which is prepared with nitrous acid.

The resulting Air was pure Fire Air. It is a particular circumstance that the Air of Fire, which had first removed the phlogiston from mercury during a slow calcination, restores it to it as soon as this lime begins to redden: but we have several facts of this nature, where heat changes the affinities of bodies with one another. The resulting Air was pure Fire Air. It is a particular circumstance that the Air of Fire, which had first removed the phlogiston from mercury during a slow calcination, restores it to it as soon as this lime begins to redden: but we have several facts of this nature, where heat changes the affinities of bodies with one another. The resulting Air was pure Fire Air. It is a particular circumstance that the Air of Fire, which had first removed the phlogiston from mercury during a slow calcination, restores it to it as soon as this lime begins to redden: but we have several facts of this nature, where heat changes the affinities of bodies with one another.

§. LXXXI.
Pyrophore.

The explanation of the inflammation of this surprising chemical has so far given unnecessary trouble. We know that it contains a material which, when heated in the open air, forces its coal to ignite. It is believed that it is a concentrated oil of vitriol which produces this heat, because the humidity accelerates it, and that, without this acid, it would not be possible to form pyrophore (25}. But can it be demonstrated that there is in the pyrophore a pure vitriolic acid, without it being united to the phlogiston?

And what is the cause of the oil of vitriol being heated with water? Why is there not Is there not the slightest heat when pyrophorus is placed in corrupt Air, which is at the same time humid, while vitriolic acid is heated in such Air when water is added to it? if my experiments will explain these curious & interesting facts. I had treated clay with oil of vitriol to make alum, I obtained a little alum,without addition of alkali: but I was left with a magma thick that did not want to crystallize.

I used part of this residue to make pyrophore. When I had calcined it as usual, I found, with surprise, that it did not ignite in the open air, and that it did not produce the slightest heat there. I took another portion; I added a little alkali and tartar to it, and I calcined it according to the usual method; I got a good pyrophore. I therefore first learned that a fixed alkali is necessary for its formation, so that it unites with the sulfur which is produced, & consequently, that the liver of sulfur plays the principal role in this operation. I knew however that the liver of sulfur does not heat up in the open air, but I believed that it could be sensibly heated by mixing it with the porous earth of the alum in the pyrophore.

I therefore mixed a strong solution of liver of sulfur with roasted alum, & I calcined the mixture strongly in a closed glass vessel, but, after cooling, I found that it did not heat up either. 'Air. I repeated this experiment, with the only difference that I mixed it with a little charcoal powder: the calcination being complete, I obtained a good pyrophore. I concluded that not only liver of sulfur was needed, but also charcoal to form it. Then I mixed a spoonful of vitriolated tartar, in fine powder, with three spoonfuls of pulverized charcoal in the same way, and I calcined this mixture on a high fire, according to the usual method. everything being cold, I also found a good pyrophore.

We see that this pyrophore cannot be formed without a fixed alkali, the alum also crystallizing with the volatile alkali, it is not surprising that we cannot make pyrophore with all the alums. I still wanted to know if humidity was essential for the pyrophore to ignite: I prepared a very dry Air, by putting small pieces of quicklime in a small flask, pushing the neck of another flask into it. ci, & by struggling with wax their joints, so that the Air communicated in the two matras. Two days later, I took off the empty matrass; I slipped half an ounce of pyrophore into it, and I sealed it as well as possible: I did not notice that it was heating up. An hour after, I put in this matrass a sponge moistened with a little water; I closed it.

A few minutes later, the pyrophore became very hot, and some pieces ignited. I also filled a matrass with Corrupted Air, and I put a little pyrophore in it, I added a moistened sponge to it: but there was no heat. I then poured it into the open air; it caught fire immediately.

So what happens in this inflammation? Pyrophore is formed by sulfur liver & coals. The liver of sulfur attracts the phlogiston which is released, while the mixture is red (I will prove later that the sulfur is likely to combine with superabundant phlogiston). This substance, composed of alkali, phlogiston and sulphur, does not ignite without humidity and the Air of Fire. The alkali, by strongly attracting the aqueous parts, is unable to retain the phlogiston any longer, especially when there is a matter there which has a great affinity with it: I speak of the Air of Fire which is door to it, and which combines with this so little adherent phlogiston.

Heat is formed which, by means of the Air of Fire, whose affluence becomes more abundant, suffices to ignite the sulfur and the coal; & as, after the combustion of the pyrophore, no more liver of sulfur is found, it must also be calcined by the heat. When we throw the pyrophore into water before it has ignited, we obtain a hepatic solution which precipitates the vinegar of litharge in black, while the solution of the liver of ordinary sulfur precipitates it in brown. The first of these solutions absorbs the Air much more readily than the last: it therefore contains a great deal of phlogiston.

When we throw the pyrophore into water before it has ignited, we obtain a hepatic solution which precipitates the vinegar of litharge in black, while the solution of the liver of ordinary sulfur precipitates it in brown. The first of these solutions absorbs the Air much more readily than the last: it therefore contains a great deal of phlogiston. When we throw the pyrophore into water before it has ignited, we obtain a hepatic solution which precipitates the vinegar of litharge in black, while the solution of the liver of ordinary sulfur precipitates it in brown. The first of these solutions absorbs the Air much more readily than the last: it therefore contains a great deal of phlogiston.

I believe that the inflammation which arises from a mixture of powdered sulfur and moistened iron filings should be explained in the same way. Experience has proved to me that sulfur does not combine intimately with iron, unless it separates a certain quantity of phlogiston from this metal. Ferruginous earth therefore has a stronger tendency to combine with sulfur than with phlogiston. If there is then found a matter capable of seizing the phlogiston which separates, there result effects conformable to the combination of these two matters.

Mix three parts of new iron filings with one part of fine sulphur, & as much water as is needed to make a thick paste: the water begins to act on the iron; it breaks the bonds of the phlogiston, the sulfur increases its action; it unites with iron half dephlogisticated: thereby the mixture takes on a black color. The expelled phlogiston adheres so weakly to the surface, that it can be removed from it very easily ( §. LIV). If there is Air in it, the Air of the Fire contained therein attracts it; heat is formed, due to the quantity of surfaces and the lack of consistency of the mixture.

Then it increases so much, by the torrent of Air of Fire which is constantly going there, that the superabundant sulfur ignites, and the whole mass is calcined. But what becomes of the phlogiston of iron, when this metal is united with sulfur in closed vessels? because this mass, melted & reduced to a fine powder, moistened with a little water, does not heat up in the air. If one pays attention to what happens during the meeting of this mixture with the Fire, it will not be difficult to answer this question. We see that in almost all the combinations which the metals which are susceptible to it form in fire with sulphur, the mixture ignites at the same instant. An effect of the same nature is produced when these mixtures take place in closed vessels.

I mixed three ounces of fine iron filings with one and a half ounces of fine powdered sulphur, & I put them in a little glass retort which was three-quarters full of them; I attached to its collar a bladder moistened & emptied of Air (§. XXX, let. h ), & I put the retort little by little on hot coals. When the bottom of the retort began to redden, the edges of the mass shone with a beautiful purple-red light, which spread more and more until the middle was also red: then the edges s darkened, and the purple light in the middle immediately disappeared. The retort always remained in the same degree of Fire during this apparition: the bladder was dilated, and an Air passed through it which occupied the space of eight ounces of water. It was flammable Air, without any kind of smell.

I have already demonstrated that light differs from heat only by a greater quantity of phlogiston. There is nothing in the retort with which the phlogiston, expelled from the iron by the sulphur, can combine. The increasing heat completely prevents me from obeying the weak attraction which would make it adhere only to the surface, & as it cannot separate from any body, without immediately combining with another (§. LXXII, n°. 5). the heat which penetrates the retort takes care of it. Can it result in anything other than light?

As much therefore as there is of phlogiston expelled from the iron, as much as it can be composed of light, and when the iron no longer furnishes phlogiston, the clarity ceases. But where does this flammable Air in the bladder come from? I have already spoken of it above, & I will soon demonstrate that this inflammable Air is composed of the matter of heat & of a greater quantity of phlogiston than is necessary to produce light.

This being supposed, it follows that in the combination of sulfur with iron, but, being found in superabundant phlogiston, it is converted with a little heat into inflammable Air. I will report some experiments that will convince people who might have some doubts about this theory. I mixed March saffron with half sulfur, and distilled as before; I saw no inflammation, & I got no Air in the bladder, but a spirit of volatile sulphur. The crocus became black & attractive to the magnet: very little sulfur had been consumed, because it had almost entirely attached itself to the neck of the retort.

It must be concluded that the earth of iron, which has been totally deprived of phlogiston, attracts it, up to a certain point, more strongly than vitriolic acid, which produces this volatile sulphurous acid. Even though this little phlogiston is not sufficient to combine this ferruginous earth with sulphur, there must be a little more: metallic iron already contains too much of it. I also mixed the same ferruginous earth with sulfur & water; I made a hollow mass of it: but this mixture did not darken and did not heat up in the air. I distilled sulfur with lead filings; I got the same dark red light: but lead not containing so much phlogiston as iron, it is not surprising that I had no Air in the bladder. This further proves that a part of the phlogiston being driven from the lead by the sulphur, it produces this light with the heat. I say part; for, by distilling a lime of lead with sulphur, galena. It is therefore also necessary for the calcined lead to unite first with a little phlogiston, before it can combine with the sulphur.

§. LXXXII.
Thundering Gold.

Here I have arrived at a phenomenon much more surprising still, that of fulminating gold. Should I have had the good fortune to discover the real cause, I will wait for what my readers will say about the consequences that I will draw from my experiments. Probably no one doubts that gold is composed of an earth which is proper to it and of phlogiston. We also know, and the most cited experiments prove it to us, that gold is indissoluble in acids, if it has not first lost its inflammable principle.

The marine acid is that of all the acids which has shown the greatest affinity with the earth of gold: however it cannot unite with this earth, if we do not add to it another matter which can attract it. phlogiston is what nitrous acid does: the decided volatility he acquires is proof of this. Gold is therefore attacked at the same time by two forces which bring about its dissolution. It can also be dissolved by dephlogisticated marine acid, which has as much affinity with phlogiston as nitrous acid.

I have shown how to prepare it, in §. LXIV of my Treatise on Manganese. Such a solution of gold contains pure marine acid, because it has taken back from the gold the phlogiston which had been taken from it by manganese. Nevertheless, if one distils strongly, the gold is reduced, and the marine acid passes dephlogisticated into the container. The reason is that the earth of gold acquiring, by means of heat, a stronger affinity with phlogiston, it takes it up again with marine acid. I have proved, in this same Treatise, that by volatile alkali we obtain fulminant gold from this solution.

This fact smooths out a great difficulty for me, by showing me that nitrous acid is not necessary for the production of fulminant gold. The earth of gold having separated from its solution with the metallic luster, I am sure that it has taken on phlogiston again. The metals precipitate it in this form, but not their earths. The fixed alkalis decompose the gold solution, but slowly. The metals precipitate it in this form, but not their earths. The fixed alkalis decompose the gold solution, but slowly. The metals precipitate it in this form, but not their earths. The fixed alkalis decompose the gold solution, but slowly. I call earth gold the precipitate which comes from it: the volatile alkali precipices it more quickly, and it is this precipitate which is properly the object of this §.

The earth of gold is capable of combining with volatile alkali: a sort of salt similar to this combination results .

I digested thirty grains of gold with a little spirit of sal ammoniac, prepared with lime, I sweetened this earth, & dried it very gently: it weighed thirty-seven grains, & was converted into fulminating gold. I see, in a Dissertation on fulminant gold, presided over at Uppsala by the famous Bergmann, that sal ammoniac also gives fulminant properties to gold.

This Dissertation served as a guide and helped me a lot in my research. I digested a solution of Glauber's sal ammoniac with this earth, I found this solution a little sour, which proves that the volatile alkali had attached itself to the gold earth, which, after sweetening, was real fulminating gold. It follows from this that the volatile alkali has more affinity with the earth of gold than with the acids.

I dissolved fulminant gold, well sweetened, in marine acid, I put in this solution a few pieces of copper. The reduced gold rushed into a fine powder: I filtered the solution & evaporated it, after which I added a little alkali from tartar. I obtained in the container, by distillation, a veritable volatile alkali. It is not very extraordinary that the earth of gold combines with this alkali, several metallic earths having this property; which further strengthens my opinion that all earths are species of acids (LXXIII).

The ignition of Thundering Gold produces a species of Air.

I took a glass tube a finger thick and half an ell long, the extremity of which ended in points. I plunged the pointed side of the tube into the water, so that a third of it remained empty; I plugged this tube under water; & withdrew it from the water, the height of which I observed in the tube: then I held the tube a little horizontally, & I introduced into it approximately a speck of fulminating gold, observing well that this empty side was not wet : I also closed this extremity with a cork which joined well, I held the tube in the same position above a lighted candle, & I heated the place where the fulminant gold was. A few hours after the ignition and the perfect cooling of the tube, I opened its end, which ended in a point, some water squirts out. I repeated this experiment several times with the same success. The Air produced occupied the space of one and a half big water.

Curious to know the nature of this Air, I mixed very exactly half a large fulminant gold with three large vitriolated tartar, I put this powder in a small glass retort, to the neck of which I attached an empty bladder of 'Air, & I placed it on hot coals. As soon as the heat had penetrated, the mixture became a dark brown; damp vapors & a little white sublimate rose in the neck of the retort, & the bladder was dilated.

The retort cooled, I tied up the bladder and detached it: the sublimate weighed about two grains, and was nothing but ordinary sal ammoniac. The Air of the retort was impregnated with the smell of alkali. I poured hot water over the residue; the vitriolated tartar was dissolved: only a brown powder remained, which was gold reduced to a very subtle powder.

The Air enclosed in the bladder also smelled of volatile alkali; it occupied the space of six ounces of water, and its properties were 1°. to be immiscible with water, 2°. not to precipitate the lime water, 3°. to turn off the light. This Air was perfectly similar to that produced by the destruction of volatile alkali. I have adduced certain proofs of a similar kind of destruction of volatile alkali, in my Treatise on Manganese. In general, whenever a body attracts the phlogiston of volatile alkali, one of its constituent parts, one always obtains this species of Air. I obtained it later in several ways: namely, from a mixture of March saffron & sal ammoniac, distilled in a retort fitted with a bladder, & from the white precipitate obtained from mercury sublimated by volatile alkali. .

This precipitate is composed of mercurial earth, sal ammoniac & a little water. Air, produced by the detonation of flaming nitre, is for the most part of this species. whenever a body attracts the phlogiston of the volatile alkali, one of its constituent parts, one always obtains this species of Air. I obtained it later in several ways: namely, from a mixture of March saffron & sal ammoniac, distilled in a retort fitted with a bladder, & from the white precipitate obtained from mercury sublimated by volatile alkali. . This precipitate is composed of mercurial earth, sal ammoniac & a little water.

Air, produced by the detonation of flaming nitre, is for the most part of this species. whenever a body attracts the phlogiston of the volatile alkali, one of its constituent parts, one always obtains this species of Air. I obtained it later in several ways: namely, from a mixture of March saffron & sal ammoniac, distilled in a retort fitted with a bladder, & from the white precipitate obtained from mercury sublimated by volatile alkali. . This precipitate is composed of mercurial earth, sal ammoniac & a little water.

Air, produced by the detonation of flaming nitre, is for the most part of this species. of a mixture of March saffron & sal ammoniac, distilled in a retort fitted with a bladder, & the white precipitate obtained from mercury sublimated by volatile alkali. This precipitate is composed of mercurial earth, sal ammoniac & a little water. Air, produced by the detonation of flaming nitre, is for the most part of this species. of a mixture of March saffron & sal ammoniac, distilled in a retort fitted with a bladder, & the white precipitate obtained from mercury sublimated by volatile alkali. This precipitate is composed of mercurial earth, sal ammoniac & a little water. Air, produced by the detonation of flaming nitre, is for the most part of this species.

To see if it contributed anything to the inflammation of the fulminating gold, I filled a vial with aerial acid; I put a little fulminant gold in it: I closed the vial, and I placed it in the dark in hot sand. The inflammation took place as usual.

I conclude from these experiments, that fulminant gold being always composed of volatile alkali & the earth of gold, that the inflammation of fulminant gold cannot take place without heat, that heat being formed of phlogiston & Air of Fire, that the earth of gold attracting more strongly the phlogiston than the Air of Fire (§. XXXIX), I conclude, say I, that it is the heat which produces the reduction of fulminating gold.

But, the Air of Fire being disengaged, it immediately combines with the inflammable principle of the desiccated volatile alkali, this salt having no affinity with gold: then there is more phlogiston than there is. enough to produce ardour ; it always results in light. The Air which the phlogiston has abandoned in the volatile alkali, recovers its elasticity, it is rendered still more energetic by the phlegm, the sal ammoniac & the volatile alkali being all converted at once into elastic vapours, finally by the production from the ardor , it makes an effort on the Air which surrounds it, and communicates to it the movement of the undulation necessary for the explosion.

I believe that sal ammoniac, obtained in distillation, does not belong to fulminant gold. No doubt the fulminating gold retains a little marine acid: this separates from it during the distillation at the same time as the volatile alkali, and this sal ammoniac is formed. I also think that fulminant gold contains more volatile alkali than Fire Air can destroy. I judge that the Air of Fire is in a condition to decompose the volatile alkali, because a piece of this alkali, thrown into a white-hot crucible, immediately ignites. I still believe that if it were possible to combine the earth of gold intimately with coal, fulminant gold would result. I mixed gold earth with a little coal dust in a small glass which I put in burning sand. Right after, the earth of gold was reduced, and the coal ignited. I'ardor was not the cause of this inflammation, for the charcoal powder, projected on the same sand, did not ignite. It would surely burst into flames, if the Air of Fire were more abundant.

Air is a dulcified elastic acid.

§. LXXXIII.

I exposed, in the preceding experiments, the two next principles of the common Air, it was not necessary any more to give a clear idea of ​​the Fire. I am going to go further and examine whether Air is still susceptible to other decompositions.

First experience.

I put a rat under a matrass which could hold four pots of water, I gave it bread softened with a little milk, and I closed the matrass with a wet bladder: it lived thirty-one hours. I held the matrass upside down under the water, and I pricked the bladder: two ounces of water got into it. It is likely that this small amount came from the heat of the rat, which had forced air out of the matrass before I could close it.

§. LXXXIV.
Second Experience.

I took a large flexible bladder; I fitted a tube to its opening: I filled it with the air from my lungs, holding the tube & the bladder with my right hand & the closed nostrils with my left. I breathed this air as long as I could; I was able to breathe in twenty-four times (it is remarkable that at the end I drew all the Air contained in the bladder at once, while I barely needed half of it at the beginning), I stopped up with a finger the pipe, & I tied the bladder. The Air it contained had the same properties as that in which the rat had perished: it contained the thirtieth part of aerial acid, which I separated from it with the milk of lime, a lighted candle went out in it immediately. following.

§. LXXXV.
Third Experience.

I locked up a few flies in a vial into which I had introduced a paper coated with a little honey: they died in a few days, without having absorbed any Air, but the whitewash reduced the Air in the vial. a quarter, & the remaining three quarters extinguished the Fire.

I took a flask which could hold twenty ounces of water, I drilled a hole in it near the bottom with the corner of a broken file (Fig. 5 A), I put in this flask a small piece of quicklime, & I closed the opening with a stopper, through which I had first passed a tube: I surrounded the stopper with a large circle of pitch, on which I overturned a jam glass which contained a large bee & a paper smeared with honey, I sunk the glass far enough into the pitch, so that no air got into it; I put the vial in the tank D filled with water, so that half of the vial was covered with it; I put a small weight on the glass, to prevent the vial from being lifted by the water, which rose a little every day into the vial through the small opening A. I took care to stir it a little from time to time, so that the cream which formed on the whitewash would break up. In seven days the water was raised to E, and the bee was dead. I tried putting two bees at a time in glass C: the same amount of Air was converted into air acid in half the time. Caterpillars & sparrows provided the same results.

§. LXXXVI.
Fourth Experiment,

I put some peas in a little matrass holding twenty-four ounces of water, I half-covered them with water, & I closed the matrass: the peas sprouted roots, & germinated. Within a fortnight, I realized that they were no longer profiting. I held the matrass under the water, & opened it; the air was neither increased nor decreased, but the whitewash absorbed a quarter of it, and the residue extinguished the flame. I kept separately in matras fresh roots, fruits, herbs, flowers & leaves: a few days later, the fourth part of the Air was likewise converted into aerial acid. The flies suddenly perished in this Air.

§. I.XXXVII.

It is particular that the animals which have lungs, do not perceptibly absorb the Air, that they only charge it with very little aerial acid, and that this Air nevertheless extinguishes the flame, while the insects and the plants convert a quarter of it into aerial acid. I wanted to know if it was not the Air of Fire which had been transformed into aerial acid, because in these experiments there had been as much Air changed into aerial acid as the common Air or that of the matras contains. of Fire Air.

§. LXXXVIII.
Fifth Experiment.

I mixed in a bottle, of a capacity of twenty ounces, one part of Air du Feu with three parts of the preceding Air, in which the peas no longer grew, and from which I had separated the marine acid.

I had first filled the bottle, & I had put four peas in it, after which, I had flowed into a bladder, containing the Air of the Fire , the fourth part of this water, & the surplus in another bladder which contained this corrupt Air (§.XXX, let. g ) , observing that the peas did not fall into the bladder, and that there remained enough water in the bottle to cover them halfway. I saw the peas rise, & when they no longer profited, I found likewise that the Air was not absorbed, but the whitewash made almost the fourth part of it disappear. It is therefore the Air of Fire which is converted into aerial acid. Peas do not grow in three parts acid air & one part fire air. I mixed the Corrupted Air from the §. XXIX with Fire Air, I got the same result, that is, Fire Air was also converted into air acid.

§. LXXXIX.
Sixth Experiment.

I mixed, in the same proportion, the Air spoiled by the peas with the Air of Fire, I filled a bladder with it. I strongly exhaled the Air from my lungs, & I inhaled this mixture as many times as I could; after which, I found that it contained very little aerial acid, and that it extinguished the flame when this acid was separated from it. I believe that the effect which animals with lungs produce on the Air must be attributed to the blood contained in the vessels of the lungs. The following experience authorizes me to do so.

We know that the surface of newly drawn blood takes on a beautiful red color in the open air, and that the lower parts also redden when the air strikes them. Would Air undergo a change here? I filled a third of a matras with freshly drawn ox blood, closed it hermetically with a bladder” & often turned the blood upside down in the bottle. Eight hours later, I found in this Air neither diminution of volume, nor airy acid, but the light went out there immediately. This experiment had been made in winter: thus, one cannot attribute its effect to putrefaction; for, twelve days later, this blood was still fresh: besides, there is no putrefaction without the production of aerial acid.

I still wanted to see what the effects of L'air du Feu would be on animals and plants.

§. XC.
Seventh Experiment.

[a] I put two ounces of nitre in a small glass retort on hot coals, & I fitted a large bladder softened by water (§. XXXV): I boiled the nitre, until I would have obtained in the bladder three quarters of a pot of Air du Feu, I tied the bladder and I detached it from the retort. I put a tube in its opening, and, after having emptied my lungs well, I breathed the Air from the bladder (§. LXXXIV), which happened very well. I managed to breathe up to forty times (24), before it became sensitive to me, finally I exhaled it as best I could. It did not seem to have diminished much: the light could still burn in a glass filled with this Air. I inhaled it again up to sixteen times: then it extinguished the flame, but I found only a few vestiges of aerial acid. this Air has the property of letting Fire burn. I believed that the amount of humidity might have prevented me from inhaling this Air as many times as I could; I therefore repeated the same experiment, with the only difference that I sprinkled the bladder with a handful of potash. I breathed this Air sixty-five times, before I was forced to stop. The light only burned for a few seconds in that Air.

§. XCI.
Eighth Experiment.

I plugged the hole A & the tube B of the vial ( Fig. f ), & I filled it with Air from the Fire (§. XXX, e ). I had in my hand a jam glass, lined with paper coated with honey, and containing two large bees. I opened the tube, I put the glass on top as quickly as possible, pushing it into the circle of pitch. I then placed this device in tank D, filled with milk of lime, and I uncorked the hole A. The milk of lime rose a little daily in the vial. At the end of eight days the vial was completely filled with it, and the bees died.

§. XII.
Ninth Experiment.

Plants hardly profit in the Air of Fire. I filled with this Air a flask holding sixteen ounces of water, into which I had introduced four peas: they actually sprouted roots, but did not rise at all. The whitewash absorbed the twelfth part. I poured this Air into another vial which also contained four peas. Fifteen days having elapsed, the peas had roots, and there was just as the twelfth part of the air of absorbed by the whitewash. I repeated this experiment three more times with the same Air, and I noticed that the fourth & the fifth time, the peas had risen a little. Having made these experiments, I was left with half of the totality of the Air, and the Fire could still burn in it. There is no doubt that if I had continued this maneuver, all the air of Fire would have been converted into aerial acid. It is remarkable that the peas, while they are growing from the roots, have more action on the Air of Fire than they have afterwards.

§. XCIII.

It is therefore the Air of Fire which maintains the circulation of the blood and the juices of animals and plants so well. It is surprising that the lungs do not produce the same effect on the Air of Fire as insects and plants. These converting it into aerial acid & the lungs into corrupted Air (§. XXIX, LXXXIX, XC), it is difficult to say the reason: I will try it however. We know that the addition of phlogiston to acids deprives them of their properties, sulfur, volatile nitrous acid, arsenic regulus, sugar, &c, prove it. I am tempted to believe that the Air of Fire is composed of an infinitely subtle acid and of phlogiston, and it seems probable to me that all acids owe their origin to the Air of Fire. So when this Air penetrates the plants,

It cannot be objected to me that one obtains, by the destruction of plants, such a large quantity of aerial acid, that they must indeed attract this Air: for, if that were the Air of the vials which contained my peas, would have been almost entirely lost. Let us remember what I have demonstrated on the constituent parts of heat & light, & observe that no plant being able to grow without heat, it is quite natural that they decompose it as well as light (25 ): for this decomposition requires only a perfect separation of the phlogiston from these delicate matters, a repair which can be effected by the capillary tubes which are so subtle.

This phlogiston, by retaining very little acid & mixing with a little water, is converted into oil. Two things contribute to make me believe it: the green resin, which is formed, after a few days of exposure to the sun, in the plants which one withdraws almost white from a dark cellar, & the production of inflammable Air, which is just a very subtle oil. However one could say to me, that if the plants indeed attracted the phlogiston of the Air, the aerial acid should be lighter than the Air, which is contrary to the experiment, since it is really heavier. But this objection does not destroy my opinion: for all acids stubbornly retaining water, aerial acid must have the same property, and consequently its greater weight may be attributed to water.

It still remains for me to explain why the blood and the lungs do not transform the Air of Fire into aerial acid, like insects and plants. Here is what I think in this regard. Phlogiston, which makes most of the bodies with which it combines fluid, elastic and mobile, must have the same effect on the blood. The red corpuscles attract it through the subtle pores of the lobes of the lung, it divides them, makes them more fluid, it animates their color (§. LXXXIX): the circulation rids them of this phlogiston, and puts them in a state to absorb again that of Air, in the lungs where they are most immediately in contact with it. I invite scientists to carry out experiments which will enable them to decide what has become of this phlogiston during the circulation of the blood. Fire & extinguishes Fire like aerial acid.

I still have one experience in store, to prove that blood actually attracts phlogiston (26), which is to have removed its phlogiston from inflammable Air through my lungs , and to have transformed it into corrupted Air.

I filled a bladder with Air obtained from a mixture of iron filings & vitriolic acid (§. XXX, let. c), I breathed it in as described in §. XLVIII; I could hardly take twenty breaths, and after recovering a little, I exhaled the Air as best I could: I breathed it again. I was forced, after ten aspirations, to cease: this Air no longer ignited and did not combine with the lime water, in a word, it was corrupted air.

I maintained, for half an hour, in continual boiling, a piece of sulfur which I had put in a retort which could contain twelve ounces of water, to which I had adapted a bladder instead of a receptacle, & which I had arranged in such a way that the sulfur which rose in the neck could fall back into the retort. After cooling, the Air was neither increased, nor diminished; it had a slight hepatic odor and extinguished a light. I will demonstrate later that sulfur is capable of taking hold of phlogiston again; & this experiment seems to prove that a little of the phlogiston of the Air is attached to the sulphur, & that by this deprivation this Air has acquired the nature of corrupted Air.

It is, however, remarkable that other substances which attract phlogiston still more strongly, such as, for example, fuming nitrous acid, do not remove it from the air. It is still surprising that I could only breathe in the inflammable Air twenty times, & I observe, as an extraordinary thing, if I do not I will demonstrate later that sulfur is capable of taking hold of phlogiston again; & this experiment seems to prove that a little of the phlogiston of the Air is attached to the sulphur, & that by this deprivation this Air has acquired the nature of corrupted Air. It is, however, remarkable that other substances which attract phlogiston still more strongly, such as, for example, fuming nitrous acid, do not remove it from the air.

It is still surprising that I could only breathe in the inflammable Air twenty times, & I observe, as an extraordinary thing, if I do not I will demonstrate later that sulfur is capable of taking hold of phlogiston again; & this experiment seems to prove that a little of the phlogiston of the Air is attached to the sulphur, & that by this deprivation this Air has acquired the nature of corrupted Air. It is, however, remarkable that other substances which attract phlogiston still more strongly, such as, for example, fuming nitrous acid, do not remove it from the air. It is still surprising that I could only breathe in the inflammable Air twenty times, & I observe, as an extraordinary thing, if I do not which attract phlogiston still more strongly, such as fuming nitrous acid, for example, do not remove it from the air.

It is still surprising that I could only breathe in the inflammable Air twenty times, & I observe, as an extraordinary thing, if I do not which attract phlogiston still more strongly, such as fuming nitrous acid, for example, do not remove it from the air. It is still surprising that I could only breathe in the inflammable Air twenty times, & I observe, as an extraordinary thing, if I do not I'm wrong, that about a quarter of an hour later I felt very hot. Note further that the Air of Fire, corrupted by the lungs, extinguishes Fire. Why doesn't aerial acid attract phlogiston again? why doesn't Corrupt Air attract him? Mr. Priestley says he transformed aerial acid into wholesome Air, by means of a mixture of dry filings & a little water.

Each time I wanted to repeat this experiment, the aerial acid was always absorbed by the filings. I reduced the molten iron filings with the superabundant sulfur to a fine powder, I moistened it with water, & I kept it in a bottle filled with aerial acid, but with the same result: the acid air was almost completely absorbed within two days. Mr. Priestley further asserts that by shaking the corrupted Air in the water, he had restored it: I also failed in this experiment. I filled a quarter of a flask with corrupted Air & the surplus with fresh water, I closed the flask exactly, & shook it in all directions for almost an hour after which, the light went out again in this Air.

Mr. Priestley succeeded in mixing the inflammable Air of the metals with the water: I could not succeed in this, although I had used only a little inflammable Air and a great deal of water. He also observed that plants made the corrupt Air salubrious (27), while it follows, on the contrary from my experiments, that they spoil the Air. I held in the dark, & I exposed in the light of the sun,

§. XIV.

Water has the particular property of decomposing the immediate principles of Air, of combining with the air of Fire, and of contracting no union with corrupt Air.

1°. I filled a large bottle with boiled water, barely cooled, and I poured out the tenth part of it: then I held the bottle under water, open and upside down. Each day the Air decreased in the bottle, & this decrease ended, I transferred the residue of the Air into a bladder (§. XXX, h), & from the bladder into a vial ( §.XXX, e ): j I introduced a light into it: hardly had it entered the vial when it went out.

2°. I then took the water so I had removed the Air, I filled a bottle with it, & I poured the tenth part of it into a bladder full of corrupted Air: I overturned my bottle in a vat of water, & I observed the space that the Air occupied in the bottle. Fifteen days later, the water had not absorbed any of it.

3°. I put a large bottle without a bottom in a deep boiler, so that the water from the boiler exceeded the head of the bottle, to which I attached a bladder emptied of Air, and I let a single broth fall into it. water. The Air contained in the water, which was spilled in the bottle, rose in the bladder, which I tied & detached from the bottle. I filled a vial with this Air, and I introduced a small light into it:

This Air of Fire, dissolved in water, is as indispensable to aquatic animals as to terrestrial animals: they attract it into their bodies & convert it into corrupted Air or aerial acid. Whatever this transformation, it is necessary that this Air abandon water, water not retaining the aerial acid in the open air, and not combining with the corrupted Air (n°. 2), so that she is again able to dissolve the Air of Fire & supply it to the animals. My experiences agree with these ideas.

I left a few leeches to die in a bottle half filled with water and well sealed. I examined the Air which was above this water: it had no more odor than it; it seemed to have increased a little, & he extinguished the Fire. It seems that these animals lived only on the phlogiston of the Air of Fire, & perhaps also on that of heat. I kept it for two years in the same water: the glass was only covered with a simple pancake.

It is easy for me to discover the presence of the Air of Fire in the water. I take, for example, an ounce of water, I pour into it about four drops of a solution of vitriol from March & two drops of alkali from tartar, weakened by a little water: a precipitate immediately results. dark green, which turns yellow a few minutes later, when the water contains Fire Air: but in boiled & cooled water, without having had any communication with the free Air, or in distilled water recently, the precipitate retains its green color, & does not turn yellow until an hour later, & if it is kept in full flasks & without any communication with the Air, it does not turn yellow.

I have already proved (§. XV) that the color of the green precipitate of iron must be attributed to phlogiston, still adhering to its earth: whence it follows that the Air of Fire is in a condition to attract phlogiston, though not in its elastic form. Here is an experiment which also demonstrates that aquatic animals attract the Air of Fire from water. I put a leech in a flask completely filled with water, and preserved from the access of the air: two days later, it was almost dead. I examined the water by the method indicated, and found that the precipitate retained its green color. Fire that water contains.

Fill a flask with water, put a few peas in it: in twenty-four hours you will find the water charged with aerial acid, but no Air of Fire. Peas swell only slightly in boiled & cooled water; which explains to me why the water decanted from above the plants not only loses its smell, but also deposits a viscous substance when the bottles are often opened, while these waters always retain their smell and their clarity in full glasses. All plants communicate to water some viscous parts which it retains by transferring it. Fire Air is the main cause of this deposit. By entering the water, it attracts the flammable principle of this subtle, oily & viscous substance,

Heat is a constituent part of different bodies.

§. XCV.

I think, according to §. XCIII, do not deceive me, in admitting that the Air of Fire is a dulcified elastic fluid, a subtle acid, combined with a little phlogiston, capable of varying its properties, according to the more or less inflammable principle to which it is united . Thus heat is also a particular acid which contains a certain quantity of phlogiston: it must, according to its nature, combine with substances which have an affinity with acids or phlogiston. The resulting effects of these combinations, are therefore principally due to heat, the alkalis, the absorbent earths, the metallic limes, are the matters which really combine it with the heat & which, by this means, form with it different kinds of salt. neutral. It follows further that these bodies are forced to let the heat escape,

Take neutral salts so that the acid can be separated by heat alone, such as fixed alkalis, calcareous spar, white magnesia, metallic earths, lime & magnesia dissolved in nitrous acid, magnesia dissolved in marine acid, &c. Make them blush white, for half an hour, in open or closed vessels, to calcine them, & keep them, after they have cooled, in small stoppered flasks: these will be the same kinds of earth as before the calcination, with the difference that instead of being combined with nitrous, marine & aerial acids, they will be combined with heat. Some are likely to retain more heat than others; also their properties differ due to their amount of heat, as the proportion of aerial acid and other acids influences the properties of several earths capable of receiving more or less of these acids.

Those which have attracted the most heat are not only soluble in water, but also lose their heat therein. This heat, as a subtle acid, acts in this like several other acids, such as phosphoric, arsenical, spathic and aerial acids, which, perfectly saturated by the earth, produce salts insoluble in water, while it easily dissolves these salts when they are formed with excess acid. but still lose their heat there. This heat, as a subtle acid, acts in this like several other acids, such as phosphoric, arsenical, spathic and aerial acids, which, perfectly saturated by the earth, produce salts insoluble in water, while it easily dissolves these salts when they are formed with excess acid. but still lose their heat there.

This heat, as a subtle acid, acts in this like several other acids, such as phosphoric, arsenical, spathic and aerial acids, which, perfectly saturated by the earth, produce salts insoluble in water, while it easily dissolves these salts when they are formed with excess acid. The fixed alkalis, lime, the earth of the heavy spar (*), are of the number of these salts, & become soluble in water, by means of the heat with which they come out combined, & the water expels the heat from them. superabundant: hence it is that they heat up with it, although I have not observed that the earth of heavy spar produces sensible heat with water. Lime precipitates from the water in a state of lime.

(*) Heavy spar earth is a particular kind of earth which, when calcined, dissolves in water like lime; but this water decomposes the gypsum solution. This results in a precipitate which is regenerated heavy spar. This earth fuses with Fire, and forms, with nitrous acids, neutral salts which crystallize and which do not moisten with Air. The solution of gypsum also decomposes these salts, and likewise regenerates them with heavy spar.

Pour alcohol into lime water, it will precipitate lime which will be susceptible to further dissolution in water, which proves that heat does the function of menses in lime which always remains an insoluble salt in the spirit-of-wine, and it is for this reason that the quicklime does not heat up in the spirit-of-wine.

The acids can dissolve the calcined earths of which we have just spoken, and cause there a vehement heat, because they decompose the neutral salt in question, and they entirely expel the heat. Put a thermometer in the lime water, & pour into it a little water saturated with aerial acid; thermometer liquor will rise a little. If the acids that are poured on the calcined earths or on the alkalis are combined with absorbing earths, no heat results, although this substance is really driven out, because a double decomposition takes place here.

We reproduce a real lime, by mixing a solution of fixed sal ammoniac & very caustic alkali: the heat combines with the calcareous earth, & the marine acid with the alkali. Pour an acid on this lime, and you will immediately feel warm. If calcareous earth contains more heat than other earths, which, despite being strongly calcined, are indissoluble in water, it is necessary that by decomposing Epsom salt, for example, by milk of lime, vitriolic acid combines with calcareous earth, & heat with magnesia: but, this one not being able to attract as much heat as lime, the superfluity of this heat mixes with water.

I left a thermometer in whitewash for an hour, after which I added Epsom salt solution to it: the liquor immediately rose in the tube. The metallic earths, although they are indissoluble in water, must nevertheless attract a great quantity of heat, judging by the great increase in weight which they acquire in their calcination, whether during the calcination they have attracted the Air of Fire by the action of their phlogiston, produced by means of heat, whether they have abandoned their phlogiston to Air, and attracted the heat of Fire. It is enough that there is Air of Fire in these limes, to attribute their excess of weight to it. I say that these limes must attract a great quantity of heat, because one can, with excess of heat, make them soluble in water. I pulverized fresh litharge, I poured into it a solution of fixed sal ammoniac, diluted in water: I put the whole thing in a vial which I shook often. During the interval of a few hours, the solution deposited calcareous earth, & I obtained a good lime water which decomposed it in the air, & precipitated the corrosive sublimate in yellow.

By digesting a solution of sea salt with litharge, a caustic mineral alkali salt is obtained. Bodies, combined with excess heat, such as alkalis, lime, litharge, & form soaps. By pouring an acid into a solution of soap, the acid combines with the alkali, the heat is released, and this heat not being sensible, it has to combine again. It meets the oil with which it unites, and this oil acquires, by means of it, the particular property of dissolving in large quantities in the spirit of wine, and of forming a particular soap with the spirit of wine. volatile sal ammoniac, prepared with lime, properties that fatty oils also acquire after a few distillations, because during these distillations they seize the heat of the Fire.

Heat is also interposed in the pores of certain salts, as in white-calcined vitriol, in fixed sal ammoniac, in the foliated earth of tartar, &c. but the water can drive it out. Concentrated vitriolic acid and phosphoric acid, being sufficiently fixed to Fire, are capable of receiving a good portion of heat, and although the other mineral acids cannot attract it from Fire, for lack of fixity, they are not less proper to combine with it in great abundance. In this they resemble volatile alkali: for, when sal ammoniac is distilled with a caustic fixed alkali or quicklime, the heat of this caustic salt combines with the volatile alkali, and the acid of the salt. ammonia with lime.

If this volatile alkali meets an acid, the heat is very sensibly removed from it. The same is true of weak mineral acids. Pour into a retort oil of vitriol on sea salt; adapt a container containing a little water to the neck of the retort: ​​the water will heat up without fire, because the vitriolic acid combines with the alkali of the sea salt, which releases the heat which immediately joins with marine acid: but she will be forced to abandon it as soon as it has combined with the water in the container.

This fact explains the following phenomenon. The oil of vitriol, poured over salt, bubbles while remaining cold, while its vapors heat up in the Air. I am convinced that this heat is not a new product, but that it comes only from the humidity of the Air. There is nothing extraordinary about the bubbling, since dry marine acid is always elastic. The smoldering nitre spirit also heats up with Air & Water. It is remarkable that the heat releases some acids, and that these acids in their turn drive out the heat without the help of the Fire.

Several similar affinities are known in chemistry, which heat reverses in the same way. Perhaps the following experiment will clarify this point for us. I filled a flask with aerial acid, I put a little well pulverized and newly calcined lime in it, I corked the flask exactly, and I overturned it in a vase containing oil. Eight days later, I opened my overturned vial under water, and I saw, with surprise, that no water entered it; but as soon as he could get in a little, the Air was absorbed. Would these kinds of salts first lose their water by heat, and would the desiccated acids then have less affinity with absorbent substances than heat? These observations prove the great difficulty of obtaining an acid or a pure earth, and I do not think I am mistaken in saying that no one has yet succeeded in doing so.

§ XIV.
Flammable Air.

If heat is a subtle acid, it must be capable of combining with more or less phlogiston, and although all acids do not have the property of attracting phlogiston in large quantities, most of them, however, are in a state of take on it excessively. Heat is one of the latter: it becomes light with very little more phlogiston, and forms with still more phlogiston flammable Air.

Iron is formed from an earth of its own, combined with a certain portion of phlogiston and heat. All metals have this in common with it, and their difference consists only in their earth, which, according to their nature, is found united with more or less phlogiston. metals, or if it only fills their pores, it is enough for me that it exists in metals. The more phlogiston a metal contains, the more heat it has; no metal is dissolved by acids, except by the laws of a double affinity. The acids combine with their earths, & the released phlogiston unites with these same acids: but, if these acids have no affinity with the phlogiston, the Air attracts it, &, in its absence, it joins the heat which is expelled at the same time from the metals by the acids. This then results in effects specific to similar compounds.

When the oil of vitriol, diluted in water, meets the iron, it first combines with its earth: but this weakened acid not having a decided affinity with phlogiston, and the Air not being able to reach Up to the iron enveloped by the acid, there remains no other resource for the phlogiston than to combine with the heat of the iron, and to produce with it inflammable Air. The heat which is felt during this dissolution is that which could not touch the phlogiston immediately enough to be converted into inflammable Air. If the phlogiston can combine with another body, the heat will be much greater, because the heat will be released from the phlogiston. This is what happens when you pour nitrous acid on iron filings. zinc gives, with these acids, the same results as iron.

Nitrous acid does not destroy flammable Air. I filled a glass with the latter, and I poured into it a little fuming nitrous acid: the acid did not redden, the Air was not absorbed, and, a few days later, it caught fire again. as before. I cite this experiment to prove that inflammable Air does not exist fully formed in metals. If it were, nitrous acid could disengage it, as it disengages aerial acid from chalk.

Flammable Air being composed of heat & phlogiston, it is not surprising that this Air seems to disappear entirely with the Air of Fire, & that it does not even leave any trace of aerial acid or other substances of that nature for rendering (§.XIX, XLVI) (28), when its phlogiston combines with the Air of Fire. Simple water can produce inflammable Air with iron: the foam, which always appears on the surface of water which has remained for a few weeks on iron filings by stirring it a little, is none other anything but flammable Air. This Air is still obtained by distilling iron filings with sal ammoniac.

And indeed, how would phlogiston remain in iron, while marine acid combines with its earth, & that the volatile alkali has no affinity with the inflammable principle? I can disabuse those who would be tempted to believe that acids contribute to the formation of flammable Air. Mix some zinc filings with a little caustic fixed alkali in a glass retort provided with a bladder, & distill, the alkali will attack the earth of the zinc, & you will have inflammable Air in the bladder. It will be the same by digesting zinc with the spirit of sal ammoniac. the alkali will attack the earth of the zinc, and you will have inflammable Air in the bladder. It will be the same by digesting zinc with the spirit of sal ammoniac. the alkali will attack the earth of the zinc, and you will have inflammable Air in the bladder. It will be the same by digesting zinc with the spirit of sal ammoniac.

The caustic fixed alkali being composed of heat and pure alkali, we understand that by putting it with an inflammable substance, the acid of which, combined with the phlogiston of this substance, is attracted by the alkali with a superior force. to that which binds it to phlogiston, there will result a double decomposition, and which the heat of the alkali will produce with the phlogiston of inflammable Air.

Sulfur would not be suitable in this experiment; its acid holds the phlogiston too strongly for the alkali to separate it from the vitriolic acid. The carbon there is the cleanest, it is a sulfur formed from phlogiston and aerial acid. If we grind it with alkali made caustic by lime or fire, and distill it over open fire in a glass retort lined with a bladder, we obtain a large quantity of flammable air which does not contain aerial acid. The alkali, on the contrary, has lost its caustic favor, and effervesces with the acids. We see, in this experiment, why the hot coals burn with a blue flame in the furnaces.

No one will believe that this flame comes from an oil which still remains in the coal. Could it be doubted that this oil had long been expelled from it by the vehemence of the heat? I half filled a small retort with very dry crushed charcoal, and I fitted a bladder emptied of Air into it. As soon as the retort was hot, the bladder dilated, and when the fundus began to redden, the dilatation ceased. While I let the device cool, the Air came back from the bladder into the coals. The volume of this Air was about eight times greater than that of the coals. I heated the retort again, the air came out of it and went back in again while cooling.

I repeated this maneuver very often with the same result. This Air extinguishes the Fire, and contains a little aerial acid. When the spoiled Air was expelled from the coals, & while the retort was still red, I substituted for the first bladder a new bladder containing fresh Air: this new Air was absorbed by the coals, and the ardor of the Fire brought it out, but it was converted into corrupted Air. I have observed that these coals attract still a greater quantity of aerial acid: wheat and deer's horn, reduced to coals, do not furnish such air. When the coals give no more Air in the bladder, and the Fire is pushed vigorously, so that all their mass becomes red, another kind of Air is obtained. I forced the Fire until the bladder stopped expanding, and I let it cool.

Part of this Air entered the retort; but there remained a great deal of it in the bladder: it was inflammable Air. I applied the Fire once more to these coals; but I only obtained approximately the quantity of Air which had returned from the bladder into the retort during the cooling, and which occupied eight times more space than the coals. So I took them out of the retort & lit them a little in the open air: I left them to cool, & distilled once more. From the beginning, & before the retort turned red, corrupted Air rose from it, & when the coals were kindled, they again produced a great quantity of inflammable Air for me.

I let the apparatus cool down again, then I forced the fire so much that the retort began to melt; but I got very little Air. It is therefore necessary to ignite the coals in the open air, so that they still supply Flammable Air into the retort. Coal containing alkali & lime is destroyed by a double affinity: the alkali, or the liberated lime, combines with the aerial acid & the heat which penetrates the retort with the phlogiston. When the alkali is saturated with aerial acid, it can no longer form inflammable Air: but, if you burn a little charcoal in the open air, it will reappear as alkali, and by this means it can Flammable Air occurs again in the retort.

One obtains, in the same way, a large quantity of inflammable Air, by distilling charcoaled deer's horn over a large Fire. the alkali, or liberated lime, combines with the aerial acid & the heat which penetrates the retort with the phlogiston. When the alkali is saturated with aerial acid, it can no longer form inflammable Air: but, if you burn a little charcoal in the open air, it will reappear as alkali, and by this means it can Flammable Air occurs again in the retort. One obtains, in the same way, a large quantity of inflammable Air, by distilling charcoaled deer's horn over a large Fire.

the alkali, or liberated lime, combines with the aerial acid & the heat which penetrates the retort with the phlogiston. When the alkali is saturated with aerial acid, it can no longer form inflammable Air: but, if you burn a little charcoal in the open air, it will reappear as alkali, and by this means it can Flammable Air occurs again in the retort. One obtains, in the same way, a large quantity of inflammable Air, by distilling charcoaled deer's horn over a large Fire. & by this means flammable air can be produced again in the retort. One obtains, in the same way, a large quantity of inflammable Air, by distilling charcoaled deer's horn over a large Fire. & by this means flammable air can be produced again in the retort.

One obtains, in the same way, a large quantity of inflammable Air, by distilling charcoaled deer's horn over a large Fire.

The flame of coal is therefore formed when the heat which is between the burning coals combines with their phlogiston, and a part of aerial acid unites with their ashes. The inflammable Air does not ignite in the mass of coals, because the Air of Fire which is interposed there, is already saturated by their phlogiston: it must rise and reach the Open air, which is why the burning coals, which enclose large spaces between them, seem to burn on their surface.

It is a remarkable thing, that the Air of Fire, which is so subtly divided by a certain proportion of phlogiston, as observed in heat & light, becomes so gross when phlogiston is more abundant, to the point that it can be stored in jars. Although we do not discover, or that there is only very little aerial acid in the inflammable Air drawn from the coals, we will nevertheless find a good portion of it after the combustion of this Air, even when we would have separated from it before, with milk of lime, the little that it could contain, which proves that this inflammable Air has volatilized a little carbon, like arsenical acid in digestion with zinc, produces an inflammable Air which contains a little arsenic regulus.

Could this subtle dissolution of coal, and its introduction into the blood, be the cause of the great danger of the vapors of coal? or that there is only very little aerial acid in the inflammable Air drawn from the coals, one will however find a good portion of it after the combustion of this Air, even when one would have separated from it before, with milk of lime, the little it could contain, which proves that this inflammable Air has volatilized a little carbon, like arsenical acid in digestion with zinc, produces an inflammable Air which contains a little regulus arsenic.

Could this subtle dissolution of coal, and its introduction into the blood, be the cause of the great danger of the vapors of coal? or that there is only very little aerial acid in the inflammable Air drawn from the coals, one will however find a good portion of it after the combustion of this Air, even when one would have separated from it before, with milk of lime, the little it could contain, which proves that this inflammable Air has volatilized a little carbon, like arsenical acid in digestion with zinc, produces an inflammable Air which contains a little regulus arsenic.

Could this subtle dissolution of coal, and its introduction into the blood, be the cause of the great danger of the vapors of coal? which proves that this inflammable Air has volatilized a little carbon, like arsenical acid in digestion with zinc, produces an inflammable Air which contains a little arsenic regulus.

Could this subtle dissolution of coal, and its introduction into the blood, be the cause of the great danger of the vapors of coal? which proves that this inflammable Air has volatilized a little carbon, like arsenical acid in digestion with zinc, produces an inflammable Air which contains a little arsenic regulus. Could this subtle dissolution of coal, and its introduction into the blood, be the cause of the great danger of the vapors of coal?

§. XCVII.
Air smelling of sulfur (29).

1°. I mixed quicklime in fine powder, with an equal portion of sulfur powder: I simmered the mixture in a small glass retort, lined with a bladder emptied of air. A little sulfur rose in the neck of the retort, but no air appeared. I poured marine acid on this liver of sulfur: there was a lively effervescence, accompanied by a strong hepatic odor. This mixture heated only slightly.

2°. I took a part of well ground manganese & a part of sulfur powder, I simmered the mixture in a retort provided with a bladder. The superabundant sulfur sublimated, and I obtained in the bladder a spirit of volatile sulfur. The rendering had a green color; it effervescent with the acids, and smelled of liver sulfur.

3°. I prepared caustic alkali with lime & tartar. It heated itself briskly with the acids, but without effervescence. I melted it with sulfur in a covered crucible, to make hepar. This liver of sulfur made a kind of effervescence with the acids which heated it little.

4°. I collected, in separate bladders, this Air obtained by the operations which I have just reported: it had the following properties. 1°. It did not precipitate the lime water: 2°. the water absorbed quite a large quantity of it, took on a strong hepatic odor, and its flavor was sweet: 3°. a light suddenly went out in this Air, but it ignited a mixture of one part of this Air & two parts of common Air.

The vial in which the ignition took place filled with a thick white cloud which smelled of the spirit of volatile sulphur, and it deposited a white powder which was sulphur.

5°. I mixed coal dust with sulphur, & distilled in an empty bladder. First I got Corrupted Air; after which, I substituted another bladder, & reinforced the Fire: which produced me an Air smelling of sulphur, perfectly similar to the preceding ones. To see if sulfur furnished this kind of Air with the only heat, as well as this same heat, combined with phlogiston, produces inflammable Air, I put a piece of sulfur in a retort, to which I fitted a bladder. , & I maintained the sulfur, for half an hour, in strong boiling. The Air neither increased nor decreased in the retort, but it was converted into corrupted Air, & not into Air smelling of sulphur. The phlogiston of coal therefore influences the production of this Air.

6°. I filled a retort with inflammable Air, in which I had put a little sulfur, & I boiled the sulfur as above: I placed the retort in both experiments, so that the sulfur sublimated could, being melted by the heat, flow into the retort. After cooling, the Air of the retort is, indeed, smelly, but insoluble in water. It seems that this inflammable Air contains too great a portion of phlogiston, which hinders dissolution.

7°. This sulphurous inflammable Air appears to be a compound of heat, phlogiston & sulphur.

I filled a phial with this Air, I poured into it a little fuming nitrous acid, and I closed it with a tight stopper: the phial was immediately full of thick red vapours. Half an hour later I turned the flask, and I uncorked it under the water which was introduced into it immediately, and which filled three quarters of it. The water took on a little sulfur.

8°. I filled a flask again with this Air, I poured a few more drops of fuming nitrous acid into it. The spirit of wine from a thermometer which I immersed in it immediately rose, and a yellow powder which was sulfur precipitated.

9°. We see at no. 4, that after the combustion of this Air, there also precipitated sulphur, doubtless coming from the spirit of volatile sulphur, separated from the portion of sulfur which had been inflamed.

I hermetically sealed a vial full of this Sulfur-stinking Air, into which I had poured a little volatile sulfur spirit. Half an hour later, the glass was coated on the inside with a yellow sulphurous film, and the air was largely absorbed. I repeated the experiment, plunging a thermometer into the vial: the spirit of wine rose noticeably. I poured a little arsenical acid into this Sulfur Air; the acid became yellow, and a veritable orpiment precipitated. The spirit of dephlogisticated salt also absorbs this Air, and precipitates the sulfur from it, but the marine acid produces no change in it.

I therefore think that when the phlogiston, by means of which the sulfur and the heat combine together, is removed from this Air, it decomposes entirely, because the heat must be released from it, and the sulfur precipitate. We may further conclude that the spirit of volatile sulfur has an affinity with phlogiston.

Alkalis and lime only dissolve sulfur when they are caustic: the heat which these salts contain must be the principal cause of their adhesion to sulphur. By adding to it an acid, that called salt, for example, it combines with calcareous earth or alkali; it releases the heat: but, as it does not become sensible, it must form a new combination. This heat not being able to unite with the sulfur which emanates at the same time, unless phlogiston is still added to it (no. 5), it attracts the inflammable principle of a portion of the sulphur, and unites with as much of the released sulfur as is necessary to form the Air smelling of the sulphur.

This is still better explained by gypsum, vitriolated tartar, or even the spirit of volatile vitriol, which is always found in the alkali, after the sulfur has been precipitated, which is a natural consequence of decomposition. of a part of sulfur in the production of this Air. By pouring a lot of acid at the same time into a solution of sulfur with the alkali, less stinking air is formed, and a subtle oil is observed in the mixture: but this oil does not remain fluid, it thickens & harden in the open air. It seems that this large quantity of acid, by removing the alkali too quickly, opposes the decomposition of sulfur, or reduces it to very little, that consequently the heat does not find enough phlogiston to convert stinking sulfur into vapors. The operation is therefore only begun, and the result is an oil.

The formation of this Sulfur Air with sulfur & fatty substances, must be attributed to the same cause. I distilled, in a retort lined with a bladder, a mixture of sulfur & olive oil. As soon as it started boiling, the bladder was dilated: I got an Air smelling of sulphur. Sulphur, phlogiston & heat being united here, this production is not surprising. The best method of obtaining this Air is to melt in a retort three ounces of iron filings with two ounces of sulphur, to maintain the heat, until the sulfur no longer sublimates, and to break the retort when everything is cooled: the weight of the iron will be increased by one ounce. This sulfur iron dissolves with great effervescence in acids, & only air stinking of sulfur is obtained, without any sulfur remaining in the residue.

The superabundant phlogiston of the iron was released from it during the fusion, and combined with the heat of the Fire; which is the cause of the light which appears (§. LXXXI). The rest of the phlogiston is exactly in the proportion necessary to form, with the heat of the iron, a combination which produces a stinking air, with the sulfur liberated at the same time with it by the help of vitriolic acid (No. 6). ).

END.

TRANSLATOR'S NOTES .

(1) M Lavoisier urged one of his friends to read, in one of the Public Sessions of the Royal Academy of Sciences of 1776, his Memoir which contained the ideas on this subject: they seemed very extraordinary, & only germinated in the head of a small number of physicists. Unfortunately, we are prone to receive novelties rather badly: they shock our self-esteem, and disturb the small circle of ideas that we had formed for ourselves. See the Memoirs of the Royal Academy of Sciences , vol of 1777, & the Opusc, Chim, of M. Lavoisier.

(2) It is the dephlogisticated Air of Priestley. See Note 4.

(3) Volumes had been written on the conversion of water into earth, until Mr. Lavoisier, having taken up this question again by experiments of a very delicate kind, thought he had finished it in a Memoir printed in the Collection of the Royal Academy of Sciences for the year 1777. More recently M. l'Abbé Fontana, recalling the opinions of Boyle, of MM. de Machy, Macquer, Margraff, handed us over to a more fully informed ( Journal de Physique, Tom. XIII, year 1779)- The experiment reported by Mr. Scheele brings us back to the conclusions drawn by Mr. Lavoisier: it is directly opposed to the assertion on which Father Fontana bases his indecision. He claims that the polished & the transparency of the glass are not attacked by the water placed in digestion: moreover, this difference may come from the more or less saline composition of the glasses which these two scholars used .

(4) This is a misprint in the German Edition , there should be dephlogisticated instead of phlogisticated. I will scrupulously preserve the nomenclature of M. Bergmann & M. Scheele, so that my translation will be more rigorously exact. It is not that I had more willingly used the word acid or chalky gas, adopted by M. Bucquet, instead of that of fixed air or aerial acid, and the term gas that our chemists prefer for other aeriform substances, to avoid the reproach of naming Air substances very different from those which are commonly designated by this word, atmospheric Air. Besides, this can only shock people who are unaware of the matter. Mr. Scheele gives the name of spoiled Air , of corrupted Air, to phlogisticated gas. The name Air du Feu , fever luff, which Mr. Scheele gives to dephlogisticated Air, could perhaps have been translated as igneous Air. However, I did not dare to use this expression, because it seems to me that it would mean that Fire is a part of the dephlogisticated Air, while, according to Mr. Scheele, the dephlogisticated Air is a part of the dephlogisticated Air. constituent parts of Fire.

(5) This has been a generally recognized truth for many years. It should be noted that this work appeared in 1777.

(6) This supposes that Scheele's Fire Air still contains phlogistic acid, and it is doubtless for this reason that Mr. Bergmann criticizes Mr. Priestley for having given it the name of dephlogisticated Air.

(7) M. le Roy, who was unaware of this Translation, read, at the very Session of the Academy of Sciences, in which I asked for Commissioners to examine it, this observation of M. Bergmann, M. Portal tells us a this occasion, that Carminali had published a vol. in 4°, entitled, if I am not mistaken: De suffocat Animalium , which was filled with experiments on extinguished irritability in asphyxiated animals. Moreover, since M. Bergmann published this Foreword, all our Authors, who have written on asphyxiated persons, have done research on the causes of their death, and on the way in which gases act on animals. We also took care of it in Germany. We especially know the work of Mr. Achard.

(8, §. IV) Or by fermentation,

(9, §. V) In the word, particular species of Air . I have already said it, I would prefer to call, with Mr. Macquer, aeriform elastic fluids, gases, and not Airs, to avoid any ambiguity. See Note 4.

(10, §. VIII) Common Air is composed of three fluids, Fire Air, Corrupt Air & Aerial Acid; which at first seems contradictory with the title, which admits of only two kinds. But it is relative to the faculty of receiving phlogiston that the Author makes this distinction; & in this case, he doubtless includes aerial acid & corrupted Air under the same species, as neither being capable of disengaging phlogiston. We believe we should observe on this occasion, that M. Lavoisier was the first who advanced that the air of the atmosphere is composed of the union of several elastic fluids.

(11, §. XXIV. Title) See. the Note of 5. VII.

(12 §. XXX) The apparatus in use today is infinitely more convenient than Mr. Scheele's method. Thus, the details contained in this §. become almost superfluous: but I did not think it necessary to remove them, they do honor to the imagination of the Author. They were absolutely necessary when he published his work.

(13) Apparently, this is the German alder which is two inches shorter than the half-alder of France. I do not take the liberty of reducing this measurement to feet and inches, although this was more in conformity with the use of our language, because there could be in Sweden a yardstick still different from that of Germany. However, the Book being written in German, this cannot be assumed.

(14) Ardor, fiery heat.

(15, §. LVIII) So it is with iron; its elasticity increases with the proportion of phlogiston. Could we not say, following the principles of our Author, that quenching produces its effect on excessively phlogisticated iron, because water has a great affinity with heat, that it seizes sensible heat iron, & that it thereby prevents this heat from combining with the free Air which would release a large quantity of this phlogiston by the influx of the Air from the Fire which it contains, instead of the water on the contrary only releases phlogiston combined with the Air of Fire in sensible heat? It envelops the steel on all sides, and its phlogiston, unable to be in immediate contact with the Air of Fire, remains fixed. It can remain there peacefully, when the sensible heat has been removed by quenching, because the pores of the metal are no longer dilated, and the Air of Fire can no longer strike it directly. It is true that it takes very little to break one's bonds. See §. LXXIX.

(16, §. LXVI) See the Memoirs of Mr. Sennebier, Librarian of the Republic of Geneva, as well as the various objections that have been made to him in the Journal. de Physique, years 1776-1780, moreover, the observations of M. Opoix on the colors, and especially the researches on the cause of the changes of colors of MM. Edward, Huffey of Laval.

(17, §. ibid. ) This observation is common to MM. Becari, Meyer, Schulze & Sennebier.

(18, §. LXXtI) Consult again here the Works quoted in Note 16 .
(19, §. ibid. , Note ) This is to ask why we cannot compose oils with phlogiston, aerial acid & water. The Author admits them as constituent principles of oils, although it is impossible to make oil with these substances. It is the same with several other matters which we cannot form in our laboratories, although their constituent parts are known to us. This refutation would therefore not destroy the opinion of M. Baumé, if there were not yet other opinions against it.

(20, page 176 , in the Note ) Physicists attributed to the density of the Air, the speed with which the wood is consumed in extreme cold, & the ardor & the clarity of our chimney fires in times severe frost; but they did not know that these effects were due to the abundance of Air of Fire that the density of the Air accumulates around the burning bodies.

(21, §. LXXVII) Much more, one sees there a halo, a veritable flame, according to the experiments of MM. Macquer, Lavoisier, Cadet, Darcet & Rouelle.

(22, §. LXXJX) In beating the lighter to light a candle, I have often grown impatient that the sulfur of the match should not ignite until after all the tinder has been reduced to charcoal, provided nevertheless that the piece of tinder was not of excessive size. Apply a moderately sulfured match to a small piece of tinder which begins to burn; far from lighting up, it will extinguish the place where you will put it. The match will only catch fire when the whole piece of tinder has been converted into charcoal, often even the sulfur melts, & flows on the tinder without burning; & when the tinder is totally ablaze, we see the flame of the molten sulfur appear on its coal. Approach the match only when the tinder is in this state: the sulfur ignites on the spot. The tobacco only catches fire in the pipe when the tinder is consumed. Mr. Scheele's theory shows us the cause. The phlogiston, which releases it in great abundance from the tinder to which it adheres only weakly because of the cowardice of its tissue, seizes all the Air of Fire contained in the surrounding Air, which prevents sulfur or tobacco from letting out their phlogiston, then the latter, no longer being attracted by the tinder, can act on the sulfur or the tobacco, and both ignite. It is well to observe that when tinder is held by one of its extremities, so that one of its surfaces does not rest on another body, such as the flint with which it is lit, or the tobacco enclosed in a pipe, it ignites sulfur or any other very combustible substance, almost as quickly as when it is reduced to coal, because in this case it is in contact with more of the Air of the Fire. , the common Air surrounding it on all sides, while when it rests on some other substance, it communicates with the common Air only by one of its surfaces,

(23, §. LXXXVII) Messrs. Proust & Beuly having made pyrophores without alum & without vitriolic acid, this explanation falls by itself. See the new Dictionary of Chemistry by M. Macquer, & the Journal of Physics, Supplement to the year 1778.

(24, §. XC} See the analogous experiments made by Abbé Fontana, Journal de Physique, 1780, Tome XV, pag. 99-110.

(25, §. XCIII) See the experiment of Bernard-Christophe Meese, on the influence of light on plants , and the Memoir of M. Sennebier, inserted in the fourteenth Volume of the Journal de Physique , pag. 368 & 369, 467 & 474 .

(26, §. IX) See Note 23.

(27, §. XCIII, towards the end) The experiments of M. Ingen-Houze explain this contradiction to us. See also the numerous experiments of M. Mangues on this subject.

(18, §. XCVI) By reiterating a certain number of explosions in the same vessel, with a mixture of inflammable Air & Air of Fire, the walls of the vessel & line with a whitish dust which has been examined, if I am not mistaken, by M. l'Abbé Fontana, or by M. de Volta.

(29, §. XCVII) We have given it the name of Hepatic Air.

Extract from the Registers of the Academy, August 8 , 1781.
MM. Lavoisier & Bertholet having reported on a translation made by M. Dietrich, of a work by M. Scheele, entitled: Observations Chimiques & Experimentes sur l'Air & sur le Feu, the Academy judged this work worthy of be printed under its Privilege: in witness whereof I have signed this Certificate. In Paris, August 8, 1781. The Marquis de Condorcet .