Antoine Laurent, a celebrated chemical philosopher, was born at Paris on the 26th of August 1745. His father being a man of opulent circumstances, spared no cost on the education of his son, who soon gave a decided preference to the physical sciences. 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, our author, although at that time only 21 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 alternately occupied with the pretended conversion of water into earth, the analysis of the gypsum found in 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 mineralogical kingdom, serving 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 gales gases was just made known to the learned world, by Black, Priestley, Scheele, Cavendish, and Macbride, which appeared like a new creation.

About the year 1770, 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 have over every physical research. He was inspired with the true spirit of inductive philosophy, and all his experiments had a direct reference to general views. He published his chemical opuscules in the year 1774, 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 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 made to carry 120 toises instead of 90. 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 were published in 1789, which is a beautiful model of scientific composition, elegant, clear, and logical. His celebrated system was almost universally adopted in a very few years, so full was the conviction it carried along with it to every candid, reflecting mind. The last of Lavoisier's philosophical works was on the perspiration 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 45 ounces; that he consumes 33 ounces of vital air, or oxygen; that 8 cubic feet of carbonic acid gas are discharged from his lungs; that the weight of water discharged from the lungs is 23 ounces, composed of 3 of hydrogen and 20 of oxygen, which interesting discoveries he directed to the improvement of medicine.

There are no fewer than 40 memoirs of Lavoisier in the volumes of the Academy of Sciences from 1772 to 1793, full of the grand phenomena of the science; such as the analysis of atmospheric air, the formation of elastic fluids, the properties of the matter of heat, the composition of acids, the decomposition of water, &c., &c. To the sciences, arts, and manufactures, he rendered the most essential services, both in a public and private capacity. After Buffon and Tillet, he was 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 affigants, and of augmenting the difficulties of forging them. He turned his attention also to political economy, and between 1778 and 1785, he allowed 240 arpent in the Vendômois to 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.

While 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 suffered on the scaffold with 28 farmers-general on the 8th of May 1794, for no other crime but because he was opulent. A paper was presented to the tribunal, drawn up by Citizen Hallé, containing a description of the works, and a recapitulation of the merits, of Lavoisier, sufficient to make an impression on the most obdurate heart; but it was not even read by these men, who were the blind, stupid, and ferocious instruments of cruelty and death.

A man so rare and so extraordinary ought to have enjoyed the respect of the most ignorant, and even the most wicked. To produce the contrary, it was necessary that power should fall into the hands of a tyrant who respected none, and whose blind and fanatical ambition sacrificed every thing to the desire of pleasing the people.

Lavoisier was tall, and possessed a countenance full of benignity, through which his genius shone conspicuous. As to his character, it was mild, humane, sociable, 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-Anna-Pierrette-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. She had the misfortune to behold her father, husband, and intimate friends, assassinated in one day; she was herself imprisoned, and even menaced with a similar fate; but the unshaken fortitude of her mind made her rise superior to the horrors of her condition. We learn that she has since given her hand to the celebrated Count Rumford.