Chemical Effects of Caloric, Sfc. 83 



the end of this time he found them not altered. 

 They have since, however, been brought to emit 

 very sensible vapours from the more intense heat 

 of a burning glass. Hence we have some rea- 

 son to conclude, that with sufficient heat the 

 earthy substances also might be fused and vo- 

 latilized. 



V. The last of the more general effects of ca- 

 loric is COMBUSTION; but this effect is not so 

 general as the former, since there is only one 

 class of bodies susceptible of it, hence called 

 combustible bodies. 



The distinction between them and others is, 

 that the bodies which are net combustible are 

 not altered by heat in a permanent manner, nor 

 is the caloric which they receive at all increased, 

 but is readily transmitted. Combustible bodies, 

 on the contrary, are, when inflamed, sources of 

 light and heat. Their capacity of producing 

 light and heat is, however, in time exhausted, 

 and when we examine what remains we find 

 them greatly changed ; they appear to be differ- 

 ent substances, and are no longer combustible. 



All bodies that are not combustible are ready 

 to receive caloric, and part with it again, giving 

 out the same quantity, neither more nor less. 

 If a red-hot stone is thrown into a quantity of 

 water, the heat seems to be extinguished or an- 

 nihilated, but this heat is not lost. I do not 

 positively assert that caloric is never destroyed, 

 or, more properly, changed in its nature ; I only 



