Lavoisier biography larousse medical group

Air was the elastic body par excellence, playing its role in combustion, for example as a physical rather than a chemical agent. Vapors, on the other hand, were not thought to be inherently elastic but to be foreign particles dispersed and dissolved in air, just as particles of salt are dissolved in water. Nevertheless, scientists Wallerius and Eller among them had shown that water could evaporate in a vacuum, where there was no air into which the particles of water could be dissolved.

Moreover, the increase in barometric pressure in the receiver of an air pump after the evaporation of water suggested to Eller that the water had been transformed into air by combining with the matter of fire. Instead, he suggested that air, by being combined with the matter of fire, might be a fluid in a permanent state of expansion. The elements, Lavoisier wrote, enter into the composition of all bodies; but this combination does not take place in the same manner in all bodies.

There is a great similarity between the aerial fluid and the igneous fluid. Both lose a part of their characteristic properties when they combine with bodies. It is known, for example, that air when combined ceases to be elastic and occupies a space infinitely less than when it was free. In the years that followed, Lavoisier was to puzzle over this problem of the elements, with his attention focused increasingly upon the fixation of air and the possibility that the aeriform state resulted from the combination of some base with the matter of fire.

Geoffroy that certain effervescent reactions produce a cooling effect. The author of this anonymous article was the economist, philosopher, and public servant Turgot. But to Turgot not merely air, but all vapors, are expansible, a property they acquire when heat, or the subtle matter of fire, enters bodies and weakens the attractive forces binding the particles together.

Common air is simply a particular vapor, or what Lavoisier would have called an aeriform fluid; if it were possible to lower the temperature sufficiently, it should be possible to liquefy it. And Turgot made the remarkable suggestion, later taken up by Lavoisier, that all substances are in principle capable of existing in any of the three states of matter —as solid, liquid, or aeriform fluid gas —depending upon the amount of the matter of fire combined with them.

The elements, notably water, air, and fire, can exist in either of two forms, fixed or free. Up to this point, these were only private speculations which Lavoisier set down in several unpublished drafts. He had performed no experiments, and the theory derived entirely from his reading and the inferences he drew from the discoveries of others.

His eventual recognition that the atmosphere is composed of different gases that take part in chemical reactions was followed by his demonstration that a particular kind of air, oxygen gas, is the agent active in combustion and calcination. Once the role of oxygen was understood—it had been prepared before Lavoisier, first by Scheele in Sweden and then independently by Priestley in England—the composition of many substances, notably the oxyacids, could be precisely determined by Lavoisier and his disciples.

But the discovery of the role of oxygen was not sufficient of itself to justify abandoning the phlogiston theory of combustion. To explain this process, Lavoisier had to account for the production of heat and light when substances burn. At this point, we may ask what Lavoisier could have known about the work of the British pneumatic chemists other than Stephen Hales.

Although Lavoisier had the book in his library, there is no evidence that he was impressed by it. He discusses the rival views of J. In March , Priestley reported to the Royal Society the experiments that later appeared in the first volume of his Observations on Different Kinds of Air , a work only published late in Yet we can only conclude that in the book by Stephen Hales was the predominant influence in interesting Lavoisier in the chemical role of air.

Early in , at all events before June of that year, there appeared a book by the provincial lawyer and chemist Louis Bernard Guyton de Morveau, which conclusively proved that the well-known gain in weight of lead and tin when they are calcined is not a peculiarity of those metals. Guyton sought to explain these results by invoking a fanciful variation of the phlogistic hypothesis, but Lavoisier saw at once that the fixation of air might be the cause.

By August he had devised an experiment to determine the role that air might play in chemical reactions involving metals. Was air absorbed by or released from a metal when exposed to the strong heat of a burning glass? Perhaps it would be possible to answer this question by using an apparatus devised by Stephen Hales his pedestal apparatus which enabled the amount of air released or absorbed to be measured.

Soon after, however, Lavoisier learned that a Paris pharmacist, Pierre Mitouard, had reported that when phosphorus was burned to form the acid, air seemed to be absorbed. In the early autumn of Lavoisier carefully verified this report. In the autumn of he set himself to read everything that had been published on aeriform fluids. Also in two French chemists, Pierre Bayen and Cadet de Gassicourt, investigated the peculiar behavior of red calx of mercury mercurius calcinatus per se.

From this substance, they claimed, the metal could be regenerated without the addition of a reducing agent rich in phlogiston, like charcoal, simply by heating it to a higher temperature. Was this true? But before the inquiry could be made, there occurred an episode about which much ink has been spilt. In October the English chemist Joseph Priestley , during a visit to Paris, dined with Lavoisier and a group of other French scientists.

Priestley had, in fact, prepared oxygen; but at the moment he thought he had found a species of nitrous air nitric oxide , a gas he had discovered earlier. Since Lavoisier, not long after, turned to investigate this new air, Priestley may be pardoned for believing that Lavoisier was simply following his clue. Lavoisier took up this question seriously in the early months of Meanwhile, Priestley was not idle.

With a new sample of the red precipitate purchased in Paris, he again took up the investigation soon after his return to England. Prisley [sic]. Priestley, to be sure, is not mentioned. This last was to add a new dimension to his oxygen theory. Considerable progress had been made during the eighteenth century toward understanding the behavior of acids.

New acids, too, were identified; beginning with his preparation of tartaric acid in , the great Swedish chemist Carl Wilhelm Scheele added nearly a dozen organic acids to the roster of new chemical individuals, as well as preparing acids from such metals as arsenic and tungsten. The sharp, fiery taste of acids led to a confusion of acidity with the causticity of such substances as corrosive sublimate or quicklime.

The calxes of metals, Meyer thought, might contain acidum pingue. It is likely that Lavoisier at first shared the widespread notion that a universal acid, whether or not it was an acidum pingue , was to be found in the atmosphere and that this primitive acid gave rise to all the particular acids known to the chemist. His important step forward was to abandon the notion, essentially tautological, that an acid gave rise to acids and to suggest that an identifiable chemical substance, in fact an aeriform fluid or gas, played this universal role of acid-former.

Yet before the autumn of Lavoisier did not suspect that air entered into the composition of acids. He did not return to the subject until two years later. The experiments were as follows. When a known quantity of nitric acid was heated with a weighed amount of mercury, the resulting product was a white mercurial salt mercuric nitrate ; this decomposed to form the red oxide, yielding nitric oxide air nitreux.

When combined with metals, on the other hand, it forms calxes oxides. In the meantime he had extended the application of his oxygen theory of acids and had discovered that there existed related acids that differed only in the proportion of oxygen they contained, as for example sulfurous and sulfuric acids; the higher the degree of oxygenation, he discovered, the stronger was the acid produced.

The metal combines with a quantity of the principe oxigine approximately equal to that which it is capable of removing from the air in the course of ordinary calcination. From his analysis of a number of the oxyacids carbonic, sulfuric, nitric and certain organic acids oxalic and acetic , all shown to contain oxygen, he argued that all acids must be so constituted, although he readily admitted that muriatic hydrochloric acid had not been shown to contain oxygen, which indeed it does not.

Lavoisier explained this away by assuming that so far it had resisted further analysis. The limewater test was negative. What, then, was the product formed? Before this new apparatus was completed, Lavoisier used the first pneumatic chest in a spectacular experiment in which a stream of oxygen, directed into a hollowed-out piece of charcoal, burned at such a high temperature that it melted platinum, a recently described metal that had resisted fusion even at the temperature of the great burning glass of Trudaine.

Lavoisier reported his success at the public session of the Academy of Sciences on 10 April In that month the Academy of Sciences was visited by the assistant of Henry Cavendish , Charles Blagden, a physician and scientist who the following year was to become the secretary of the Royal Society. As Blagden recalled this event, the French scientists replied that they had already heard about such experiments as repeated by Joseph Priestley but doubted that the weight of water, as Cavendish claimed, was equal to the weight of the gases used.

They believed, rather, that the water was already contained in, or united to, the gases used. Accordingly, Lavoisier and Laplace put into action the newly completed combustion apparatus. On 24 June , in the presence of Blagden and several academicians, they burned substantial amounts of the dry gases and obtained enough of the liquid product so that it could be tested.

The summer and autumn of riveted public attention, and that of the scientific community including that shrewd American observer, Benjamin Franklin , upon the dramatic success of the first lighter-than-air flights. A quite different, and far more promising, solution was soon proposed and demonstrated by J. Charles, a free-lance teacher of physics.

Le Roy, Mathurin Brisson, and Coulomb, and chemists like Berthollet and Lavoisier, who—as he habitually did when serving on committees—became its secretary. Attached to this group was J. Meusnier, a young officer on leave from the Corps of Engineers. In this inquiry, carried out in his laboratory at the Arsenal, Lavoisier had the invaluable assistance of Meusnier.

In March they produced a small amount of the inflammable air by plunging a red-hot iron into water; later that month they successfully decomposed water by passing it drop by drop through an incandescent gun barrel. In this fashion Meusnier and Lavoisier prepared eighty-two pints of the light, inflammable air, and on 29 March they repeated this experiment in the presence of members of the standing committee.

Meusnier presented the results of this joint effort to the Academy on 21 April; the full memoir was published soon after. Steps were now taken to carry out with high precision a really large-scale decomposition of water into its constituent gases and its synthesis. The experiments were carried out at the Arsenal on 27 and 28 February , in the presence of members of a special evaluation committee of the Academy and other invited guests.

For the decomposition experiment, water was percolated through a gun barrel filled with iron rings; the inflammable air was collected in bell jars over water in a pneumatic though, from which it was transferred to a gasometer. In one experiment the volume of the gas expressed in weight equivalents of water was found to be equal to well over livres of water.

Lavoisier has tried to bring to this matter all the accuracy of which it is capable. In the spring of Lavoisier had enlisted the cooperation of his young colleague at the Academy, Laplace, in experiments on the vaporization of water, ether, and alcohol in the evacuated receiver of an air pump. When Lavoisier resumed his collaboration with Laplace in , the two soon undertook a famous series of experiments, using a piece of apparatus—the ice calorimeter—and a technique, both suggested by Laplace.

With their calorimeter Lavoisier and Laplace determined the specific heats of various substances, the heats of formation of different compounds, and measured the heat produced by a guinea pig confined for several hours in their apparatus. Like phlogiston, the fire matter was a weightless fluid or at least too tenuous to be weighed ; nevertheless, unlike phlogiston, which defied measurement, both the intensity the temperature and the extensive measure of the fire the heat produced in a given period of time could be precisely measured.

Originally suggested by Guyton de Morveau to eliminate the confused synonymy of chemistry, and prefaced by a memoir of Lavoisier, it emerged as a complete break with the past. In effect the scheme was based upon the new discoveries and theories, a fact aging Joseph Black to complain that to accept the new nomenclature was to accept the new French theories.

Compounds were designated, as chemists have done ever since, so as to indicate their constituents: the metallic calxes were now called oxides; the salts were given names indicating the acid from which they are formed sulfates, nitrates, carbonates, and so on. The Nomenclature—translated into English, German, Italian, and Spanish—was extremely influential and widely read.

This translation, made by Mme Lavoisier, was published in , the year after the Nomenclature chimique, and was copiously annotated with critical notes by members of the task force: the chemists Guyton de Morveau, Berthollet, and Fourcroy; the physicists and mathematicians Monge and Laplace; and, of course, Lavoisier himself. Its editors were, besides Lavoisier, his early disciples—Guyton, Berthollet, Fourcroy, and Monge—with the addition of three new recruits: the strasbourg metal-lurgist the Baron de Dietrich, Jean-Henri Hassenfratz, and Pierre Auguste Adet.

A fourth edition appeared in and a fifth in ; it was translated into English, Italian, German, and Spanish. The notes for this preface, with page reference to the Logique in the margin, cite the same passages from Condillac that Lavoisier eventually used in print. The beginning student of physical science must follow the path nature uses in forming the ideas of a child.

His mind must be cleared of false suppositions, and his ideas should derive directly from experience or observation. But a scientific Emile is not promptly corrected by nature through the pleasure-pain principle; men are not punished for the hypotheses they invent, which their amour-propre leads them to elaborate and cling to. Because the imagination and reason must be held in check, we must create an artificial nature through the use of experiment.

Lavoisier gives numerous examples of the speculative notions that often hamper the progress of chemistry. He derides the order commonly followed in works on chemistry, which begin by treating the elements of bodies principes des corps and explaining tables of affinity. On 24 November , he was arrested with many other tax farmers and were accused of defrauding the government and adultering tobacco.

After a summary trial, Lavoisier and 22 co-defendants were sentenced to death by guillotine. In , Lavoisier experimented with the burning of substances. He also repeated previous experiments of other scientists such as Joseph Black on burning alkalies, such as chalk and quicklime. Lavoisier frequently repeated experiments of other scientists not always with proper attribution.

This gave him a wide understanding of different chemistry experiments. He often came to different conclusions to the original scientists. In , Lavoisier continued experiments on lead and tin. Lavoisier undertook these experiments in sealed containers. He deduced from the experiments that the increase in weight of the metals was due to a combination with atmospheric air.

In this year, he met with English scientist Joseph Priestley, who was visiting Paris. This meeting encouraged Lavoisier to further investigate this property. In an experiment he was able to make water from burning jets of hydrogen and oxygen — this was the first proof that water was not a basic element, but actually composed of two gases.

He would also show that this element oxygen was used in respiration and heat was generated by animals who breathed in this air. We ought, in every instance, to submit our reasoning to the test of experiment, and never to search for truth but by the natural road of experiment and observation. He developed his own gasometer which could weigh gases and elements to a fine level of detail.

He later made cheaper versions available to other chemists. This is a collection of nine reprints written between and The reprints cover various aspects and personalities of the history of chemistry. Skip to main content. Lavoisier, Antoine Laurent, Person.

Lavoisier biography larousse medical group

Keep logged in. Login Register. Additional recommended knowledge. Einstein's Legacy. New York: Scientific American Library, p. ISBN Catholic Encyclopedia. New York: Robert Appleton Company. The Chemical Educator 3 5 : 1 — Retrieved on American Journal of Clinical Nutrition, Vol. Lagrange Biography English. Lavoisier intervened on behalf of Lagrange, who certainly fell under the terms of the law, and he was granted an exception.

On 8 May , after a trial that lasted less than a day, a revolutionary tribunal condemned Lavoisier, who had saved Lagrange from arrest, and 27 others to death. Antoine-Laurent Lavoisier - Chemist and Revolutionary. New York: Charles Scribner's Sons, To top. About chemeurope. Spectroscopy Apps for Routine Spectrum Analysis. Your browser is not current.

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