BAYEN, PETER, a celebrated French chemist, and member of the National Institute of France, was born at Chalons in the year 1725. His early pro pensity to study induced his friends to send him to the college of Troyes, where he went through a ro gular course of study, and imbibed a taste for natural philosophy. Anxious to improve his knowledge of chemistry, to which he was particularly attached, lie went to Paris in 1749, and studied pharmacy under. an able apothecary, the father of the celebrated Clia ras. The diligence and thirst for knowledge dis played by Bayen attracted the notice of his master, who gave him every opportunity of improvement, and entrusted him with the direction of his labora tory. From the skill which he had acquired in pharmaceutical operations, he was appointed chief apothecary to the army in Germany, during the seven years war, before he had reached his 30th year.
Upon his return to Paris, at the conclusion of the war, he was employed by government to analyse all the mineral waters in France. This labour, at first performed in conjunction with Vend, afterwards devolved upon Bayen alone, who published several works upon this important subject. His analysis of the waters of Bareges and Bagneres de Luehon, is particularly valuable, and is an admirable model for till similar researches.
The funds which were destined for these interest ing investigations having been diverted to other pur poses, Bayen abandoned the Pyrenees, and employ ed himself in the analysis of various specimens of minerals which he had collected in his travels. The results of these analyses were published in the Me moires des Scavans •ranger-es, in numerous memoirs on marbles, granites, serpentines, porphyries, jaspers, schists, and iron spar.
Bayen had the high honour of being the first who doubted the existence of the phlogistie principle of Stahl. He at first communicated his doubts to seve ral of his friends, but particularly to the celebrated Macquer, who did not approve of them. Without being discouraged at the opinion of Macquer, Bayen continued his researches, and proved, that the excess of weight, the colour, &c. of all metallic oxides, were owing to the absorption of one of the consti tuent parts of atmospheric air.
The illustrious Lavoisicr, who was then occupied with the subject of metallic oxides, happened to be present when the memoir of Bayen was read in the academy ; and, struck with the importance of the discovery, he repeated all the experiments, and was thus led to those great views by which he effected a revolution in the science of chemistry.
Bayen discovered the singular property of fulmi nating, which several metallic oxides possess, when mixed with a small quantity of sulphur. He also found, after long and difficult investigations, that tin, in its pure state, contained a very small portion of arsenic ; which, however, did not render it unfit for the purposes of civil life. He found also, that the tin of commerce, which was wrought by pew terers, contained° copper and antimony, by which it was hardened ; zinc, by which it was whitened ; bis muth, which rendered it sonorous ; and lead, which diminished its value.
Exhausted with these labours, and worn out with domestic misfortunes, Bayen died in the beginning of 1798, in the 72d year of his age. See Lassus Notice sur la vie el les Ouvrages du M. Bayen, in the Nem. Nat. Instit. (pr)