gs Chemical Philosophy, [Chap. II. 



as comprised in the following propositions. When- 

 ever a solid is converted into a fluid, it combines 

 with a certain portion of caloric, without any aug- 

 mentation of its temperature, and it is this portion 

 of caloric which occasions the change. When this 

 fluid is reconverted into a solid, the caloric which 

 produced the fluidity leaves it without any dimi- 

 nution of its temperature ; and it is this abstraction 

 which occasions the change. Thus the combina- 

 tion of a certain portion of caloric with ice causes 

 it to become water , and the abstraction of a cer- 

 tain portion of caloric from water causes it to be- 

 come ice. Water, then, is a compound of ice and 

 caloric ; and, in general, all fluids are combinations 

 of the solid to which they may be converted by 

 cold, and a certain portion of caloric. The same 

 principle, according to this philosopher, applies to 

 the conversion of liquids into elastic fluids^ or the 

 reverse ; this conversion and reconversion depend- 

 ing on the addition or abstraction of caloric. To 

 this caloric Dr. Black gave the name of latent heaty 

 because its presence is not indicated by the ther- 

 mometer. The great importance of this discovery, 

 and the extensive application which has been since 

 made of it, in explaining fluidity, congelation, eva- 

 poration, animal heat, and many other phenomena, 

 render the period of its annunciation to the world 

 one of the most interesting ceras in the history of 

 chemical science. 



In the mean time, sir Torbern Bergman, an 

 illustrious Swede, was busily engaged in exploring 

 the same de])artment of philosophy *. In the 



•* Sir Torbern Bergman was born in tht; year 1/35, ami 

 ♦lied in 1/84. lie i.s beyond all doubt, entitled to a place 



