Biographical Memoirs of P. Bay en. $J$ 



ton. He at firft communicated his doubts to fome friends, 

 and then to the celebrated Macquer, who did not approve 

 of them; The opinion of that learned man did not how- 

 ever difcourage him; and he continued his researches. It 

 was chiefly by examining precipitates of mercury that Bayen 

 convinced' himfelf fully of the falfity of Stahl's doctrine, and 

 that he acquired a proof that every thing called metallic o^d, 

 is indebted for the excefs of its weight, its colour, and its 

 ftate, only to the abforption of one of the conftituent parts 

 of the atmofpheric air. With apparatus, which he invented, 

 he made experiments fo rigoroufly corre£t, that he was able 

 to calculate the weight of this fubfiance fixed in the metals. 

 When Bayen prefented to the Academy of Sciences the 

 refult of the experiments above mentioned, Lavoifier, who 

 was prefentj mack metallic oxydes the object of his re. 

 fearches alfo. He repeated the experiments of Bayen ; found 

 them correct ; difcovcred that a portion of the air drawn 

 from metallic calces is much purer than that, of the atmo- 

 fphere; that this portion is the only part which can ferve 

 for combuftion and refpiration; and gave to this fluid the 

 name of vital air. Lavoifier therefore, by removing entirely 

 the veil which Bayen had only drawn a little afide, over- 

 turned for ever the theory of Stahl, and eftablifhed one of 

 the moft memorable epochs in chemiftry. 



The various experiments which Bayen made, in thecourfe 

 of three years, on the precipitates of mercury, led him to a 

 difcovery of the Angular property which fome of thefe pre. 

 cipitatss have of exploding with a loud noife, when mixed 

 with a very fmall quantity of the flowers of fulphur. Bayen'* 

 labours alfo in regard to tin ought not to be pafl'ed over in 

 filence. It. was a queftion in chemiftry, to determine whether 

 that metal really contained arfenic, as MargrafT and Henkel 

 had faid ; and, fuppoftng it did, whether the quantity would 

 be fufficient to make the ufe of it be abandoned in economi- 

 cal purpofes. The long and laborious refearches of Haven 

 dii'< ovcred that there exifts tin without any mixture.; and 

 P 4 fo* 



