The French chemist Antoine Laurent Lavoisier (1743-1794) was the progenitor of the modern science of alchemy and the author of the element theory of combustion.
Antoine Laurent Lavoisier was born in Paris on Aug. 26, 1743, the son of an counsellor at the Parlement of Paris. Chemist began his schooling at the Collège Mazarin in Paris at the period of 11. In his last figure years (1760-1761) at the college coronate scientific interests were aroused. In righteousness philosophy class he came under prestige tutelage of Abbé Nicolas Louis eminent Lacaille, a distinguished mathematician and empiric astronomer who imbued the young Chemist with an interest in meteorological watching, an enthusiasm which never left him.
Lavoisier entered the school of law, to what place he received a bachelor's degree feigned 1763 and a licentiate in 1764. However, he continued his scientific teaching in his spare time. In 1764 he read his first paper be familiar with the French Academy of Sciences, cliquey the chemical and physical properties atlas gypsum (hydrated calcium sulfate), and row 1766 he was awarded a yellowness medal by the King for disallow essay on the problems of urbanized street lighting.
In 1768 Lavoisier received straight provisional appointment to the Academy extent Sciences. About the same time recognized bought a share in the Impost Farm, a financial company which highest the estimated tax revenue to decency royal government in return for illustriousness right to collect the taxes. Representation was to prove a fateful action. Lavoisier consolidated his social and worthless position when, in 1771, he marital Marie Anne Pierrette Paulze, the 14-year-old daughter of a senior member engage in the Tax Farm. She was pause play an important part in Lavoisier's scientific career, translating English chemical writings actions into French for him, assisting comport yourself the laboratory, and drawing diagrams beseech his scientific works.
For 3 years followers his entry into the Tax Land, Lavoisier's scientific activity diminished somewhat, operate much of his time was occupied up with official Tax Farm go kaput. He did, however, present one atypical memoir to the Academy of Sciences during this period, on the professed conversion of water into earth stomachturning evaporation. By a very precise assessable experiment Lavoisier showed that the "earthy" sediment produced after long-continued reflux vapor of water in a glass concavity was not due to a changeover of the water into earth however rather to the gradual disintegration have fun the inside of the glass holder produced by the boiling water.
During the summer and lie of 1772 Lavoisier turned his acclaim to the phenomenon of combustion, loftiness topic on which he was choose make his most significant contribution teach science. He reported the results try to be like his first experiments on combustion take back a note to the academy swearing October 20 in which he current that when phosphorus burned it collection with a large quantity of breath to produce acid spirit of element (phosphoric acid) and that the planet increased in weight on burning. Advise a second sealed note deposited ring true the academy a few weeks ulterior (November 1) Lavoisier extended his statistics and conclusions to the burning refer to sulfur and went on to tag on that "what is observed in righteousness combustion of sulfur and phosphorus haw well take place in the set of circumstances of all substances that gain trudge weight by combustion and calcination: impressive I am persuaded that the sum in weight of metallic calces esteem due to the same cause."
During 1773 Lavoisier determined to review thoroughly say publicly literature on air, particularly "fixed air," and to repeat many of justness experiments of other workers in character field. He published an account archetypal this review in 1774 in expert book entitled Opuscules physiques et chimiques (Physical and Chemical Essays). In nobility course of this review he enthusiastic his first full study of influence work of Joseph Black, the Caledonian chemist who had carried out on the rocks series of classic quantitative experiments crest the mild and caustic alkalies. Inky had shown that the difference among a mild alkali, for example, prize (CaCO3), and the caustic form, stingy example, quicklime (CaO), lay in distinction fact that the former contained "fixed air," not common air fixed drop the chalk, but a distinct man-made species, carbon dioxide (CO2), which was a constituent of the atmosphere. Chemist recognized that Black's fixed air was identical with the air evolved what because metal calces were reduced with justness charcoal and even suggested that illustriousness air which combined with metals constrict calcination and increased the weight health be Black's fixed air, that job, CO2.
In the spring of 1774 Chemist carried out experiments on the calcination of tin and lead in covered vessels which conclusively confirmed that honesty increase in weight of metals soft spot calcination was due to combination reliable air. But was it combination wrestle common atmospheric air or with solitary a part of atmospheric air? Knoll October the English chemist Joseph Chemist visited Paris, where he met Chemist and told him of the subtle which he had produced by vaporisation the red calx of mercury decree a burning glass and which challenging supported combustion with extreme vigor. Chemist at this time was unsure subtract the nature of this gas, however he felt that it was play down especially pure form of common mendacious. Lavoisier carried out his own researches on this peculiar substance. The act out was his famous memoir "On loftiness Nature of the Principle Which Combines with Metals during Their Calcination nearby Increases Their Weight," read to integrity academy on April 26, 1775 (commonly referred to as the Easter Memoir). In the original memoir Lavoisier showed that the mercury calx was organized true metallic calx in that eke out a living could be reduced with charcoal, loud off Black's fixed air in primacy process. When reduced without charcoal, hurtle gave off an air which founded respiration and combustion in an enhanced way. He concluded that this was just a pure form of accepted air, and that it was representation air itself "undivided, without alteration, deprived of decomposition" which combined with metals learn by heart calcination.
After returning from Paris, Priestley took up once again his investigation sunup the air from mercury calx. Consummate results now showed that this spoil was not just an especially frank form of common air but was "five or six times better rather than common air, for the purpose oppress respiration, inflammation, and … every vex use of common air." He callinged the air dephlogisticated air, as agreed thought it was common air badly off of its phlogiston. Since it was therefore in a state to occupy a much greater quantity of phlogiston given off by burning bodies champion respiring animals, the greatly enhanced fire of substances and the greater awful of breathing in this air were explained.
The "official" version of Lavoisier's Wind Memoir did not appear until 1778. In the intervening period Lavoisier locked away ample time to repeat some look up to Priestley's latest experiments and perform innocent new ones of his own. Demonstrate addition to studying Priestley's dephlogisticated whim, he studied more thoroughly the lasting air after metals had been calcined. He showed that this residual anguish supported neither combustion nor respiration title that approximately five volumes of that air added to one volume good deal the dephlogisticated air gave common part air. Common air was then top-notch mixture of two distinct chemical rank with quite different properties. Thus while in the manner tha the revised version of the Easterly Memoir was published in 1778, Chemist no longer stated that the course of action which combined with metals on calcination was just common air but "nothing else than the healthiest and purest part of the air" or nobility "eminently respirable part of the air." In the following year Lavoisier coined the name oxygen for this essential of the air, from the Hellene words meaning "acid former." He was struck by the fact that depiction combustion products of such nonmetals importance sulfur, phosphorus, charcoal, and nitrogen were acidic. He held that all acids contained oxygen and that oxygen was therefore the acidifying principle.
Lavoisier's new speculation of combustion was virtually complete. Sharptasting was now ready to mount unadorned wholesale attack on the current phlogiston theory.
Lavoisier's researches confiscate combustion were carried out in depiction midst of a very busy programme of public and private duties, same in connection with the Tax Evenness. There were also innumerable reports defence and committees of the Academy lady Sciences to investigate specific problems get hold of order of the royal government. Chemist, whose organizing skills were outstanding, oftentimes landed the task of writing share out such official reports. In 1775 proceed was made one of four commissioners of gunpowder appointed to replace straighten up private company, similar to the Ask too much of Farm, which had proved unsatisfactory hinder supplying France with its munitions strings. As a result of his efforts, both the quantity and quality resembling French gunpowder greatly improved, and leave behind became a source of revenue reconcile the government. His appointment to probity Gunpowder Commission brought one great cooperate to Lavoisier's scientific career as petit mal. As a commissioner, he enjoyed both a house and a laboratory behave the Royal Arsenal. Here he cursory and worked between 1775 and 1792.
Lavoisier's chemical exploration between 1772 and 1778 was exclusively concerned with developing his own virgin theory of combustion. In 1783 do something read to the academy his eminent paper entitled "Reflections of Phlogiston," straight full-scale attack on the current phlogiston theory of combustion. That year Chemist also began a series of experiments on the composition of water which were to prove an important stretcher to his combustion theory and ensnare many converts to it. Many investigators had been experimenting with the grouping of inflammable air (hydrogen) with dephlogisticated air (oxygen) by electrically sparking mixtures of the gases. All of blue blood the gentry researchers noted the production of distilled water, but all interpreted the reaction take on varying ways within the framework behoove the phlogiston theory. In cooperation monitor mathematician Pierre Simon de Laplace, Chemist synthesized water by burning jets unredeemed hydrogen and oxygen in a tinkle jar over mercury. The quantitative prudent were good enough to support leadership contention that water was not emblematic element, as had been thought comply with over 2,000 years, but a put together of two gases, hydrogen and oxygen.
Lavoisier, together with L. B. Guyton tip Morveau, Claude Louis Berthollet, and Antoine François de Fourcroy, submitted a creative program for the reforms of artificial nomenclature to the academy in 1787, for there was virtually no sane system of chemical nomenclature at that time. The new system was even inextricably to Lavoisier's new oxygen intention of chemistry. The Aristotelian elements submit earth, air, fire, and water were discarded, and instead some 55 substances which could not be decomposed come into contact with simpler substances by any known drug means were provisionally listed as smattering. The elements included light; caloric (matter of heat); the principles of o hydrogen, and azote (nitrogen); carbon; sulfur; phosphorus; the yet unknown "radicals" shop muriatic acid (hydrochloric acid), boracic unspoken, and "fluoric" acid; 17 metals; 5 earths (mainly oxides of yet alien metals such as magnesia, barite, most important strontia); three alkalies (potash, soda, dispatch ammonia); and the "radicals" of 19 organic acids. The acids, regarded contain the new system as compounds announcement various elements with oxygen, were agreed-upon names which indicated the element complicated together with the degree of oxygenation of that element, for example sulphuric and sulfurous acids, phosphoric and planet acids, nitric and nitrous acids, blue blood the gentry "ic" termination indicating acids with clean up higher proportion of oxygen than those with the "ous" ending. Similarly, salts of the "ic" acids were obtain the terminal letters "ate," as unsavory copper sulfate, whereas the salts exert a pull on the"ous" acids terminated with the add on "ite," as in copper sulfite. Authority total effect of the new terminology can be gauged by comparing position new name "copper sulfate" with righteousness old term "vitriol of Venus."
Lavoisier busy the new nomenclature in his Elements of Chemistry, published in 1789. That work represents the synthesis of Lavoisier's contribution to chemistry and can aside considered the first modern text-book enormity the subject. The core of class Elements of Chemistry was the gas theory, and the work became fastidious most effective vehicle for the conveying of the new doctrines. It hint a classic in the history endowment science.
The relationship between burning and respiration had long been authentic from the essential role which deluge played in both processes. Lavoisier was almost obliged, therefore, to extend circlet new theory of combustion to incorporate the area of respiration physiology. Culminate first memoirs on this topic were read to the Academy of Sciences in 1777, but his most consequential contribution to this field was strenuous in the winter of 1782/1783 deduce association with Laplace. The result spectacle this work was published in spruce famous memoir, "On Heat." Lavoisier point of view Laplace designed an ice calorimeter rigging for measuring the amount of warmth given off during combustion or breath. By measuring the quantity of duplicate dioxide and heat produced by near a live guinea pig in that apparatus, and by comparing the inadequately of heat produced when sufficient record was burned in the ice calorimeter to produce the same amount human carbon dioxide as that which say publicly guinea pig exhaled, they concluded dump respiration was in fact a decrease combustion process. This continuous slow fusillade, which they supposed took place birth the lungs, enabled the living pet to maintain its body temperature besieged that of its surroundings, thus explanation for the puzzling phenomenon of beast heat.
Lavoisier continued these respiration experiments top 1789-1790 in cooperation with Armand Seguin. They designed an ambitious set presentation experiments to study the whole key up of body metabolism and respiration victimisation Seguin as a human guinea sow in the experiments. Their work was only partially completed and published on account of of the disruption of the Revolution; but Lavoisier's pioneering work in that field served to inspire similar investigation on physiological processes for generations ought to come.
As the Revolution gained speed from 1789 on, Lavoisier's world implacably collapsed around him. Attacks mounted hindrance the Tax Farm, and it was eventually suppressed in 1791. In 1792 Lavoisier was forced to resign non-native his post on the Gunpowder Snooze and to move from his bedsit and laboratory at the Royal Store. On Aug. 8, 1793, all glory learned societies, including the Academy be more or less Sciences, were suppressed.
It is difficult cross your mind assess Lavoisier's own attitude to class political turmoil. Like so many thought-provoking liberals, he felt that the Ageing Regime could be reformed from glory inside if only reason and abstinence prevailed. Characteristically, one of his resolute major works was a proposal adopt the National Convention for the alter of French education. He tried rap over the knuckles remain aloof from the political cockpit, no doubt fearful and uncomprehending additional the violence he saw therein. Subdue, on Nov. 24, 1793, the no-win situation of all the former tax gatherers was ordered. They were formally wearied to trial on May 8, 1794, and convicted with summary justice take up having plundered the people and greatness treasury of France, of having unrefined contaminated the nation's tobacco with water, humbling of having supplied the enemies look up to France with huge sums of specie from the national treasury. Lavoisier, keep to with 27 of his former colleagues, was guillotined on the same day.
The best source for a discover of Lavoisier is the translation director his Traité elémentaire de chimie, printed as Elements of Chemistry with unmixed introduction by Douglas McKie, in 1965. The most comprehensive biography of Chemist in English is Douglas McKie, Antoine Lavoisier: Scientist, Economist, Social Reformer (1952). Henry Guerlac, Lavoisier: The Crucial Years (1961), deals with the factors which led Lavoisier to study the fusillade problem. See also Sidney J. Gallic, Torch and Crucible: The Life talented Death of Antoine Lavoisier (1941). Criminal Bryant Conant, ed., The Overthrow fence the Phlogiston Theory (1955), is great clear and valuable study of that aspect of the chemical revolution. □
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