^32 CLAIMS OF LAVOISIER* 



Dr. Hales not In my former communication, I stated that Dr. Hales, froiri 



absolved air tcT ^^® *"°^* decisive experiments, shewed that the increase of 



be the cause of weight in calcination arose from the attraction and condensa^ 



weight of cat- ^'^^'^ of air : and that his conclusion obtained the notice of 



cined metals ; philosophers, is sufficicmlv evident from the following 

 but his doctrine , ^ ,-. ^, i 11 



was noticed passage taken from the treatise of the very learned and 



by ethers. ingenious Bishop Berkeley : " Fire,'' he says, " collected 



" in the focus of a glass operates in vacuo, and therefore is 

 " thought not to need air to support it. Calx of lead hath 

 '* gone off with an explosion- in vacuo, which Niewentyt and 

 ** others take for a proof that fire can burn without air. But 

 ** Mr. Hales attributes this effect to air enclosed in the red- 

 " lead, and perhaps too in the receiver, which cannot be per-* 

 " fectly exhausted. When common lead is put into the fire, 

 *' in order to make red-lead, a greater weight of this comes out 

 " than was put in of common lead : therefore the red-lead 

 *' should seem impregnated with fire. Mr. Hales thinks it is 

 " with air." * 

 Bayen's infer- In the same year, viz, l??^, in which ]M. Lavoisier publish- 

 tals are oxided ^^ ^^^ experiments on oxidation, M. Bayen delivered the fol- 

 byair. lowing opinion: '' Les experiences que j'ai faitcs me force de 



" conclure que dans la chaux mercuriale dont je parle, le 

 " mercure doit son etat calcaire, non a la perte du phlogistique 

 " qu'il n' a pas essuyee, ?nais d sa combination intime aiec le 

 *' Jluide elastiqiiCy dont le poids ajoute a celui du mercure est la 

 '' seconde cause de ^augmentation de pesanteur qu'on observe 

 " dans les precipites que j'ai soumis a I'examen." It was in 

 consequence of hearing Baycn's paper read, says Dr. Thom- 

 son, that Lavoisier was induced to turn his attention to the 

 subject."! 



It 

 increased in weight, as is found by experiment : for it is scarcely 

 possible to be conceived, whence that increase of the antimony can 

 proceed, unless from the nitro-aereal and fiery particles fixed in 

 it during calcination. It is plainly seen, that the fixation oPthe an- 

 timony arises not so much from the separation of its sulphur, as 

 from the nitro-aereal particles with which the flame of nitre 

 abounds, and which become fixed in it (viz. the antimony). 

 * Siris, 2d. edit. an. 1774, p. 91. 



t Jour, de Phys. 1774. p. 295. The first memoir of Bayen, pub- 

 lished in the Journal de Physique, for Feb._1774, is intitled Svr le 



" ' PhlogiS' 



