Popular Science Monthly/Volume 35/August 1889/Sketch of Lavoisier

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Popular Science Monthly Volume 35 August 1889  (1889) 
Sketch of Lavoisier
 
PSM V35 D454 Antoine Laurent Lavoisier.jpg

ANTOINE LAURENT LAVOISIER.


SKETCH OF LAVOISIER.

ANTOINE LAURENT LAVOISIER was born on the 26th[1] of August, 1743, and suffered death by the guillotine on the 8th of May, 1794. His family, descended from a postilion in the royal stables in the previous century, had gradually risen in estate. His father, styled in the standard biographies a "wealthy tradesman," is described by M. Grimaux, in the "Revue des Deux Mondes," as a graduate of the law school, and advocate and attorney in the Parliament of Paris. The family had also considerable wealth on the mother's side. Lavoisier's father was thus able to provide his son with good instruction, and interested himself in doing so. The youth was sent to the College Mazarin, where he was remarked as a brilliant pupil and a diligent student. Science at once became the prominent object of his studies. After leaving the college he took a course in law, and was admitted as an advocate in 1761. At the same time he began those studies by which he became eminent in many branches of science. He pursued mathematics and astronomy with the Abbé La Caille; botany with Bernard de Jussieu; mineralogy and geology with Guettard; and chemistry with Rouelle. At twenty years of age, while he seemed to give the principal share of his attention to mathematics, he became interested in meteorology, and began a series of barometric observations, which were continued through his whole life.

So interested did Lavoisier become in his studies that he was ready, in his twentieth year, to give up general society and confine SKETCH OF LAVOISIER. 549

the circle of his associates to liis teachers and fellow-students; and, pleading that his health required it, he put himself upon an exclusive milk diet. Some of his friends seem to have believed that his health was really giving way ; and M. de Troncq, send- ing him a dish of gruel, advised him in 17G3 to be temperate in his studies, and to believe that " a year longer on the earth is worth more than a hundred in the memory of men."

Among his particular friends was Guettard, who had been ad- mitted to the Academy as a botanist in 1743, but had afterward devoted himself to geology and mineralogy. He had already traveled in France and other countries in the interest of a plan he had conceived for making geological maps, upon which the kind of soil, mines, and quarries should be indicated by special marks. In connection with Guettard, Lavoisier made extensive excursions during three years through different parts of France. At the same time he studied the gypsum of the environs of Paris, con- cerning which he presented, in 1765, the first of the valuable series of memoirs with which he was to enrich the journals of the Academy of Sciences during nearly the next thirty years. His investigation included the varieties of the mineral and their solu- bility in water, and the cause of the setting of plaster, which he was the first to explain.

The Academy having, in 17Go, offered a prize of two thousand livres for an essay on " the best means of lighting at night the streets of a large city, combining clearness of illumination, facil- ity of service, and economy," Lavoisier resolved to compete for it, and began at once a series of experimental studies on the subject. In order to make his vision more sensitive to slight differences in the intensity of light, he hung his room in black, darkened it, and confined himself within it for six weeks, without permitting him- self to look upon daylight for an instant. The two thousand livres were divided by the Academy among three competitors, who had incurred considerable expense in their experiments, while it gave a special distinction to Lavoisier's memoir by awarding the king's gold medal to the author, for which a public session was given.

The geological excursions with Guettard were resumed imme- diately after the conclusion of this transaction. The intervals of leisure were given to reading, studying, and making notes ; among the fruits of which was an inquiry into the matter of fire and the nature of its elements. At first Lavoisier fancied that air was only water reduced to vapor, or rather water combined with the matter of fire ; but this gave way at once to the conception of an atmos- phere having an existence of its own and containing the fiery fluid and water in solution. Guettard's plan for a mineralogical atlas of France having been adopted by Minister Bertin, Lavoisier was

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invited to accompany liim in a tour in tlie interest of that work to Lorraine and Alsace. Among the fruits of this journey was an extended memoir on the analyses of mineral waters, which was not, however, published during Lavoisier's life. The work of publishing the atlas on the original plan proving to be a larger one than the government was ready to sustain, Guettard retired from it, and Monnet, who was no friend of Lavoisier's, took his place. He used Guettard's and Lavoisier's material, added some- thing of his own, and ignored Lavoisier, while recognizing Guet- tard, in his credits.

Other results of Lavoisier's earlier work were papers " On the Pretended Conversion of Water into Silica " (in which a prevail- ing error was refuted), " On a Species of Steatite," " On a Coal- Mine" (in conjunction with Guettard), "The Analysis of the Gyp- sums of the Environs of Paris," " Thunder," the " Aurora Bore- alis," " The Conversion of Water into the Condition of Ice," and "The Strata of Mountains" (general observations on the mod- ern horizontal strata which have been deposited by the sea, and on the conclusions that can be drawn from their disposition relative to the antiquity of the terrestrial globe). The last was not published till 1789, when it appeared in the " Memoirs of the Academy."

Lavoisier was nominated in 1768 to succeed Baron in the Acad- emy of Sciences, by Lalande, who proposed him on the ground that he had knowledge, talent, and activity, and possessed a fortune, which, relieving him from the necessity of embracing another pro- fession, would enable him to be very useful to science. His prin- cipal competitor was Jars, an eminent metallurgist. Lavoisier was chosen, but the final decision rested with the king, and his minister decided that Jars should have the seat. Out of defer- ence to the views of the Academy, a new position of adjunct chem- ist was provisionally created for Lavoisier, with the understand- ing that on the occurrence of the next vacancy in chemistry he should go in without a new election. The vacancy occurred through the death of Jars in the next year.

Desiring, as the biographers pleasantly express it, to place him- self on a financial footing in which he could pursue, independent- ly, investigations involving costly expenditures, Lavoisier sought and obtained in 1768 a position as one of the farmers-general (of the revenue). He conscientiously performed the duties of his office ; instituted reforms in taxation by removing useless duties, and earned the gratitude of the Jews of Metz by freeing them from an odious impost. M. Grimaux represents him as performing the duty of making regular tours of inspection, with which he as- sociated the study of the features of scientific interest which the places he visited might afford. The work of this oflice brought

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liim into association with farmer-general Panlze, whose daughter he married, and wlio went with him to the scaffold. In 177G Tur- got made him inspector-general of powder and saltpeter. In this capacity he made great improvements in the manufacture, so that, while he put a stop to forced official searches for saltpeter in the cellars of private houses, he quadrupled the product of the salt, and so increased the explosive force of gunpowder that the French brand became as much sux3erior to the English as it had been inferior.

Lavoisier's great work consisted in the discovery of the true functions of oxygen and the nature of combustion ; the determi- nation of the relations of the solid, liquid, and gaseous states of matter ; and in many other observations that embodied the germs of what have become since the leading principles of chemical sci- ence. Oxygen was detected at about the same time by Priestley, Scheele, and Lavoisier ; but the iDhlogistic theory of combustion possessed the minds of chemists, and, although Eck de Suchbach and Jean Rey had already dimly discerned the truth, no one had paid any attention to their discoveries, and Lavoisier was work- ing on what was to him, and substantially to the world, virgin ground. " Fixed air " and " combustible air " had been speculated upon, and " the air that is left after combustion " had attracted at- tention. But the phenomena of this kind, inconsistent as they were with the phlogistic theory, had not been sufficient to over- throw it. The first germ of Lavoisier's theory on these matters was embodied in a sealed packet which he deposited with the Academy in 1770. Recognizing that the calcination of metals could not take place without the access of air, and that the freer the access the more rapid the calcination, he " began to suspect," as he expresses himself, that some elastic fluid contained in the air was susceptible, under many circumstances, of fixing itself and combining with metals, and that to the addition of that substance were due calcination and the increase in weight of metals con- verted into calxes. From this thought came, after much groping with erroneous conclusions, the idea that air is a compound con- taining a vital part and another j^art, and that it is the vital j^art that is absorbed. The behavior of charcoal when burning in oxy- gen pointed to the nature of that substance and to the true theory of combustion. This new vital substance, which, uniting with metals, formed calxes, and with other substances generated acids, he called oxygen or the acid-producer ; the air that was left after combustion was azote, or lifeless. The inflammable air which, combining with oxygen, was found to form water, was called hydro- gen. Upon these facts, and with a few other names of known sub- stances, Lavoisier constructed the system of chemical nonienclature which, after having undergone many modifications to conform to

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new discoveries, still rules. The " muriatic radicle " gave Lavoisier some trouble, for he could find no oxygen in muriatic acid, and his experiments upon it with oxygen resulted in the production of a neutral substance which must be its calx ; and so he called chlorine oxidized muriatic acid. Such mistakes were natural in the early days of chemistry. The decomposition of volatile alkali, or ammonia, by Berthollet, led to the suggestion which Lavoisier gave out with great modesty, that many earths, still regarded as simj)le, might be compound ; and that their apparent indifference to oxygen should be attributed to their being already saturated with it.

On the nature of gases and vapors, which had not been under- stood before, Lavoisier asserted, in a memoir published in 1777, that most bodies were capable of existing in three different states — those of solids, liquids, and vapors, or aeriform fluids. The terms airs, vapors, and aeriform fluids express only a single form of matter — a class of bodies infinitely extended ; and this principle " gives the key to nearly all the phenomena relative to the differ- ent kinds of air and to vaporization." While heat tends to change volatile bodies into vapor, the pressure of the air has a contrary effect; and "the tendency of volatile bodies to evaporate is in direct ratio to the heat to which they are exposed, and inverse to the weight or pressure brought to bear upon them. Lavoisier's memoirs on heat, expansion and contraction under changes of temperature, and latent heat, show an insight into the accepted principles. He discussed with much sagacity the question whether heat is a fluid or a force ; and it would not be hard, for one who is determined to look for it, to find in his essays on this subject a prevision of the current constitutional chemistry. La- voisier's later labors were physiological. They include papers on the production of carbonic acid in respiration and the office of the lungs in the process, in which the present theory is proposed as a secondary hypothesis, and on cutaneous transpiration. In his physiological studies, M. Dumas has found that he had arrived at a remarkable anticipation of modern views concerning the re- lations of organic to inorganic nature.

Lavoisier carried his energy into several other fields, and made his mark in all. He cultivated an estate of two hundred and forty arpents in the Vendome, and in nine years doubled its production. His name is associated with a number of j^ropositions looking to the public welfare or economical reform. In 1789 he presented in the National Assembly a report of the " Caisse d'Escompte," to which he had been attached for one year. As commissioner of the treasury he proposed in 1789 a new plan for the collection of imposts, which he elaborated in a special essay entitled " The Ter- ritorial Wealth of the Kingdom of France," a work which, accord-

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ing to M. F. Hoef er, in the " Biographie g^n^rale," gave him a place in the front rank of the economists of his time. He partici- pated in the work of the commission on a new system of weights and measures. As treasurer of the Academy he set the accounts and inventories in order, and discovered some forgotten funds of the institution, and made them available. "In short, Lavoisier was to be found everywhere ; and his facility and zeal, equally admirable, were adequate for everything."

On the 2d of May, ITO-i, twenty-eight of the farmers-general, of whom Lavoisier was fourth on the list, were accused in the Con- vention of conspiring with the enemies and against the people of France. On the 6th of May they were all condemned to death, and on the 8th were executed together. Lavoisier and his friends hoped that his great scientific eminence and the undoubted useful character of his career might be brought to bear to save him. Some efforts were made to exert such influence. Lavoisier himself drew up a memoir of what he had done for the Revolution. The Bureau of Consultations presented a detailed report on his labors. A deputation of the Lycee des AHs visited him at the Concier- gerie, bearing " to Lavoisier, the most illustrious of its members," a testimonial of its admiration.

Lavoisier left no children. He is described as having had a pleasing, intellectual face, and having been of large figure and of pleasant, sociable, and obliging disposition.

His most important works were: "Opuscules physiques et chimiques" ("Physical and Chemical Worklets," 1774), "Me'thode de Nomenclature chimique" ("Method of Chemical Nomencla- ture," 1787), "Traits dl^mentaire de Chimique" ("Elementary Treatise on Chemistry," 1789). A complete edition of his works, published by the French Minister of Public Instruction, 1804-'68, included these books, fifty-eight memoirs communicated to the Academy of Sciences between 1770 and 1790, and numerous notes, letters, and reports relating to the various affairs in which he was engaged. He had himself begun to prepare a collection of his works, the completed portions of which were published by his widow in 1805 in two volumes entitled "M^moires de Chimie."

��CosGrMPTioN, according to Dr. Irving A. "Watson, prevails in all parts of New ITampshire, but is apparently influenced by topographical conditions. It is more prevalent at a low elevation with a maximum soil moisture than in the higher elevations with a less moist soil. The season has only a small influence upon the mortality from the disease ; the mortality is considerably greater among women, and no age is exempt from it ; but the least liability to contract it exists between the ages of two and fifteen, and the greatest between twenty and thirty. The death-rate is relatively much the larger among the foreign-born.

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  1. So it is given in the "Biographic Générale" on the authority of J. Lalando, and by M. Edouard Grimaux, who writes on the authority of original manuscripts and correspondence in the "Revue des Deux Mondes" for December 15, 1887. Other biographers give the 16th of August.