258 LAVOISIER. 



difficult to write so often as he has done upon the gases, 

 and the new sera which their discovery opened to che- 

 mistry, and not to have once mentioned him, who, by the 

 discovery of fixed air, was beyond all doubt the founder 

 of the system. Still more difficult was it to investigate 

 the properties of that body, ascertaining its composition 

 with new accuracy, and yet avoid all allusion to Black, 

 who had long before him proved it to be the product of 

 charcoal when burnt. The reader will search in vain, 

 either the papers on combustion, or those on acidification, 

 or those on the composition of fixed air, for the least re- 

 ference to that illustrious name. In the several Memoirs 

 upon the nature of heat, its absorption and evolution, its 

 combining in a quiescent state to form the permanently 

 elastic fluids, how difficult was it to avoid all mention of 

 him who made the great step of discovering latent heat, 

 and showed that to its absorption was owing fluidity, both 

 liquid and aeriform ! I confess that when I first read the 

 title of one of those excellent papers, " De la Combinaison 

 de la Matiere du Feu avec les Fluides evaporables, et de la 

 Formation des Fluides elastiques aeriformes," (Mem. de 

 TAcad. 1777, p. 410,) I expected to find mentioned, 

 a,t every step of the discussion, the author of this whole 

 theory, and who left it absolutely perfect, who taught it 

 from the year 1763 to crowded classes, and whose name 

 was connected with it wherever science was cultivated. 

 My wonder was not small when I found not the least 

 allusion to Black, and that the problem was completely 

 solved, how to frame an exact account of any given man's 

 discoveries and theory, never coming into contact with 

 his name. No reader of that paper could doubt that the 

 whole doctrine was that of M. Lavoisier himself; and in a 



