LAVOISIER, Antoine Laurent, the celebrated discoverer of the new chemical theory, was born at Paris in the month of August 1745. His father being a man of opulence acquired in commerce, spared no cost on the education of his son. The latter studied at Mazarin College, and obtained a great number of prizes in his classes; but he soon evinced a decided taste for the sciences, which his father had the good sense to encourage. On leaving college, he applied himself to the study of mathematics and astronomy in the observatory of Lacaiile, to that of chemistry in the laboratory of Rouelle, and to that of botany under Bernard de Jussieu, whom he attended in his herborisations. His passion for study was such, that he put himself on a milk diet, and denied himself the pleasures of general society, living only with his masters and fellowstudents, all of whom remained his friends throughout life. An extraordinary premium having been offered by the French government in the year 1764, for the best and most economical method of lighting the streets of an extensive city, Lavoisier, although at that time only twenty-one years of age, gained the gold medal; and his excellent memoir was published by the academy, of which he became a member on the 13th of May 1768. His attention was successively occupied with the pretended conversion of water into earth, the analysis of the gypsum found in [7:13:128]the vicinity of Paris, the congelation of water, the phenomena of thunder, and the aurora borealis.

By undertaking journeys with Guettard into every province of France, he was enabled to procure an immense variety of materials for a description of the mineral kingdom, and serving also as the foundation of a great work on the revolutions of the globe, two admirable sketches of which are to be seen in the Memoirs of the French Academy for 1772 and 1787. His whole time and fortune were dedicated to the cultivation of the sciences, nor did he seem more attached to one than to another, till an interesting event decided his choice in favour of chemistry. The discovery of gases, just made known to the learned world by Black, Priestley, Scheele, Cavendish, and Macbride, appeared to him like a new creation.

Lavoisier was so struck with the grandeur and importance of the discovery, that he turned all his attention to this fountain of truths, perceiving the powerful influence which this new science would exert over all physical researches. He was inspired with the true spirit of inductive philosophy, and all his experiments had a direct reference to general views. In the year 1773, he presented to’the academy, and published, his Opuscules Physiques et Chimiques, containing a history of whatever had been done before respecting the gases, and concluding with his own grand and interesting experiments. He demonstrated that metals, in calcination, derive their increased weight from the absorption of highly-respirable air, of which he afterwards proved that nitrous acid is composed. His chemical ingenuity was now so well known, that Turgot employed him in 1776 to inspect the manufacture of gunpowder, which he greatly improved in strength, or explosive force. In the year 1778 he discovered that all acids contain the respirable portion of the atmosphere as a constituent principle, and to this he gave the name of oxygen. This was the first grand step towards the new chemistry, which was fully completed by his confirming the discovery of the composition of water, ascertained in 1783.

His Elements of Chemistry, in two vote. 8vo, were published in 1789, and form a beautiful model of scientific composition, being at once clear, logical, and elegant. In a very few years his system was alm'ost universally adopted, so complete was the conviction it carried along with it to every candid and reflecting mind. The last of Lavoisier’s philosophical works was on the respiration and transpiration of animals, first read to the academy on the 4th of May 1791. By a number of the nicest experiments, he found that a man in one day perspires forty-five ounces; that he consumes thirty-three ounces of vital air or oxygen; that eight oubic feet of carbonic acid gas are discharged from his lungs; that the weight of water discharged from the lungs is twenty-three ounces, composed of three of hydrogen and twenty of oxygen; which interesting discoveries he directed to the improvement of medicine.

There are no fewer than forty memoirs of Lavoisier in the volumes of the Academy of Sciences from 1772 to 1793, all relating to the grand phenomena of the science; such as the analysis of atmospherical air, the formation of elastic fluids, the properties of the matter of heat, the composition of acids, the decomposition of water, &c. To the sciences, arts, and manufactures, he rendered the most essential services, both in a public and in a private capacity. He succeeded Buffon and Tillet as treasurer to the academy, into the accounts of which he introduced both economy and order. He was consulted by the National Convention as to the most eligible means of improving the manufacture of assignats, and of augmenting the difficulties of forging them. He turned his attention also to political economy, and, between the years 1778 and 1785, he allotted 240 arpents in the Vendomois for experimental agriculture, and increased the ordinary produce by one half. In 1791, the Constituent Assembly invited him to draw up a plan for rendering more simple the collection of the taxes; which produced an excellent report, printed under the title of Territorial Riches of France.

Whilst the horrors of Robespierre’s usurpation continued, he used to observe to Lalande that he foresaw he would be deprived of all his property, but that he was extremely willing to work for his subsistence; and it is supposed that he meant to pursue the profession of apothecary, as most congenial to his studies. But the unrelenting tyrant had already fixed his doom. He was thrown into prison, whence he was soon dragged to the scaffold, where he perished, with twenty-eight farmersτ general, on the 8th of May 1794, for no other crime but because he was opulent, and belonged to that body. A report, drawn up by Μ. Hallé, a courageous citizen, containing a description of the works, and a recapitulation of the discoveries, of Lavoisier, sufficient to make an impression upon the most obdurate heart, was presented to the revolutionary tribunal. Even Lavoisier himself deigned to ask of the miscreants who had condemned him, a delay for a few days, that he might have time to complete some experiments interesting to humanity; alluding probably to his researches on transpiration, which had been suspended by his imprisonment. But all was in vain. The president of that horrible tribunal told him, in a ferocious tone, that they had no longer any need of learned men; and his head fell under the axe of the guillotine, in the fifty-first year of his age.

Lavoisier was tall, and possessed a countenance full of benignant expression. FIis character was mild, humane, social, obliging; and he discovered an incredible degree of activity. He had great influence, on account of his credit, fortune, reputation, and his office in the treasury; but all the use he made of it was to do good; yet this did not prevent jealousy on the part of others. In 1771 he married Marie-Anne-Pierette-Paulze, the daughter of a farmer-general, whose excellent accomplishments formed the delight of his life, who assisted him in his labours, and even drew the figures for his last work. This lady had the misfortune to behold her father, her husband, and her most intimate friends, assassinated in one day; and she was herself imprisoned, nay, even menaced with a similar fate; but the unshaken fortitude of her mind enabled her to rise superior to the horrors of her condition. Lavoisier died childless.