S4/ COLLSCXroN OF MEM.OIRS. 



wliich are difengaged in effervefcence, and a great number of 

 Other chemical operations, difcovered to me demonftratively 

 the caufe of the augmentation of weight that the metals ac- 

 quire when expolcd to heat. At that time I was not ac 

 Cjuainted with J. Key's work upon the fubjed, pubhQicd in 

 1630 J and had I known it, I fliouid have confidered his opi- 

 nion in the h'ght of a vague conjecture, which did honour to 

 (he genius of the author, but required the attention of chemifts 

 in order to afcertain the truth of the opinion by experiment, 

 I was young, I had newly entered the lifts of fcience, I was 

 defirous of fame, and I thought it necelTary to take foroe fleps 

 to fecure to myfelf the property of my difcovery. At that 

 lime there exifled an habitual correfpondence between the 

 men of fcience of France atui thofe of England ; there was a 

 > kind of rivality between the two nations, which gave import- 

 ance to new experiments, and which fometimes was the caufe 

 that the writers of the one or the other of the nations difputed 

 the difcovery with the real author ; confequently I thought it 

 proper todepofit on the ift of November 1772, the following 

 note in the hands of the fecrelary of the Academy. This note 

 was opened at the meeting of the 5th of May following, and 

 mention of (hefc circum fiances marked at the (op of the note. 

 It was in the following terms : 

 He finds that " About eight days ago I difcovered that fulphur in burning, 



fulphur and f^^ f^^^^ lofing, augments in weisrht; that is lo fay, that from 

 phofphorus gam . r ri . r .i i r •. • r 



weight by com- o«e pound ot (ulphur much more than one pound ot vitriolic 

 buftion, and that acjf^ is obtained, without reckoning the humidity of the air ; 

 air abforbed. He phofphorus prefents the fame phenomenon ; this augmentation 

 infers that the of weight arifes from a great quantity of air, which becomes 

 ec^'^raT^anTdH'-^''^'^ during the combuftion, and which combines with the va- 

 engages air from pours.'* 

 litharge on re- ,, j,^-^^ difcoverv, which I confirmed by experiments which 



ducing itin ■' ' . /• 



«lofed veffels. I regard as decifive, led me to think that what is obferved in 

 the combuflion of fulphur and phofphorus might likewife take 

 place with refpeft to all ll)e bodies which augment in weight 

 by combuftion and by calcination, and I was perfuaded that 

 the augmentation of weight in the calces of metals proceeded 

 from the fame caufe. The experiment fully confirmed my 

 conje6lures ; I operated the redu<5lion of litharge rn dole vef- 

 fels with Hales's apparatus, and I obferved that at the moment 

 qf the palTage of the calx iuto the metallic flate, there was a 



difengage- 



