BAYEN (PETER), a celebrated chemist, member ' of the Institute of France, was born in 1725, at Chalons sur Marne. He showed a great inclina tion to study, and was sent by his parents to school at Troyes, where he went through a course of clas sical education with success.
The bent of his disposition was to physical science. He went to Paris in 1749, and became the pupil and friend of an eminent druggist. In this situation, he acquired a complete knowledge of the profession ; and before the age of thirty, he was appointed chief apothecary to the French army in Germany, in the seven years' war, a situation which he filled with in dustry, intelligence, and integrity.
After the conclusion of peace, he returned to Paris. The French government had employed Roa die to name chemists for the purpose of analyzing the mineral waters which are found in different parts of France, and had allotted funds for this purpose. One of the chemists named was Bayen, and he em ployed himself ardently in these analyses for several years. His analysis of the waters of Barege and of 13agneres de Luchon are published ; and besides the detail of accurate and well-contrived chemical pro cesses, they contain matter interesting to the medi cal man, to the naturalist, and even to the general reader. He resided at the above-named baths in the Pyrenees, whilst he was employed in analyzing the waters. The project of the French government was not carried farther than the analysis of these waters, so that the public employment of Bayen now ceased.
He returned to Paris, and made the analysis of different minerals which he had collected, chiefly dur ing his residence in the Alpine region of the Pyrenees ; amongst them is the marble of Campan; of which there are two varieties, the red and the green. These are brought from that country to Paris, where they make a distinguished figure in ornamental architec ture, as may be seen in the columns of the palace of' Great Trianon, in the interior of the church of St Sulpice, and in other great buildings. These analyses are published in the presenit:s a l' Academie par divers Savans, commonly called 3•1(7noires des Savans Etrangers.
He made most accurate experiments on the oxides of mercury, to show that oxidation arises from the absorption of a portion of the atmospheric air, and that the existence of the phlogiston of Stahl could not be proved. Lavoisier was present when the ac count of these experiments was read, and was em ployed at the same time in examining the metallic oxides, and it was Lavoisier that brought the subject into a clearer light, and demonstrated the nature of oxygen, and the composition of the atmosphere.
Bayen published an analysis of tin and pewter. In consequence of the writings of some German chemists, fears had arisen amongst the public, that the use of these metals in culinary vessels was per nicious. Bayen showed that these fears were without any ground, if the pewter be of the legal standard, and be not fraudulently mixed with too great a por tion of lead.
He enjoyed good health till sixty, and died at the age of seventy-six, in the year 1801. He was a man of sound judgment, of strict integrity, and acquaint ed with several other branches of knowledge be sides that which he particularly cultivated. There is a collection of his works, entitled, Opiescules Chi miques, 1798, 2 vols. 8vo. (v.)