THEORY OF COHESION. 185 



panded into vapours by the repulsive power of 

 their latent caloric. They are accordingly very 

 bad conductors, like silks, woollens, furs, and 

 other light bodies, that are full of caloric. Yet 

 by a sufficient reduction of temperature, their 

 attraction for the igneous principle is so far aug- 

 mented, that their particles are drawn closer 

 towards each other, and bound together in the 

 solid form ; and if their temperature could be 

 reduced 2000 F. there is every reason to believe 

 that their cohesion would equal that of salts, 

 rocks, or even the denser metals. 



From all the foregoing facts and arguments 

 it is evident, that hardness and softness, solidity 

 and liquidity, are not essential conditions of 

 bodies, but depend on the relative proportions of 

 aethereal and ponderable matter of which they 

 are composed ; that the most elastic gas may be 

 reduced to the liquid form by the abstraction of 

 caloric, and again converted into a firm solid, 

 the particles of which would cling together with 

 a force proportional to their augmented affinity 

 for caloric. On the other hand, it is equally 

 evident, that by adding a sufficient quantity of 

 the same principle to the densest metals, their 

 attraction for it is diminished, when they are 

 expanded into the gaseous state, and their co- 

 hesion destroyed. 



As the author has met with a few individuals 

 who cannot readily conceive how a self-repulsive 



