Translation of Key's Essai/s. 297 



advanced any thing not bearing fully on the subject; to clear 

 up which, in every point, it only remains to give a succinct ac- 

 count and refutation of the opinions which others have followed, 

 or follow ; and to solve the objections that might be made to 

 my answer. 



Essay XVII. 



It is not the disappearance of the celestial heat which animates 

 the Lead, or the death of the latter that increases its weight 

 in calcination. 



Of all, as far as I know, that have written on this questlon,^ 

 Cardan is the first, who, in his fifth book, De Subtilitate* , says, 

 that lead, by conversion into ceruse, or by calcination, gains 

 one-thirteenth part in weight, and gives this reason for it — The 

 lead dies, for the celestial heart, which was its soul, vanishes ; 

 whose presence gives it life, and renders it light ; as its absence 

 occasions its death, and makes it heavy. This he confirms 

 by the example of animals, which become heavier after death,, 

 from the extinction of the celestial heat, the soul, (as he thinks), 

 both of animals and all other mixed and compound bodies. 

 This opinion is defective, to say no worse of it, in many re- 

 spects. First, in attributing life to lead. Secondly, in sup- 

 posing that the presence of the celestial heat makes it light,, 

 and its absence heavy. Thirdly, because it assigns the same 

 reason for the increased weight of lead by calcination, and of 

 animals by death. There is nothing of the kind. For as to 

 life, how can lead possess it, since it is a homogeneous body, 



* Note by M. Gobet. 



" Nam plambum cum in ccrussam vertitur, ac uritur, tertia decimi 

 parte sui puuderis augetur. Hoc fit, quia calor ille coelcstis evanescit:. 

 nam certum est, adjici uihil, ct tamcii crescit : turn igitiir par ratio eliam 

 in animalibus videatur, qua; graviura morte fiunt, quuniam cxhalante 

 •nima, srcum calor ctiam, ac quicquid ab iilo est claboratiim evanescit :. 

 manifestum est corpora metailica, et luj jdcs ipsos etiam vivcre." (Lib. v.. 

 ik mittione et rni»<M.)_Cardani, t/e Sublililale, lib. xxi. Parisiis, 15jK 



This auilior aUo observed, tliui a tile {jains weight in burning. 

 Vol. XII. X 



