AEROSTATICS. 



2. Caloric converts solids into liquids, by overcoming 

 their cohesion so far, that the particles attract one 

 another with forces that are as a certain function 

 of the distances (and of the distances only) of the 

 particles from one another. This produces the 

 equilibrium of the particles, or their tendency to 

 obey the action of any force in any direction. The 

 addition of more caloric, so as entirely to overcome 

 the attraction of the particles for one another, con- 

 verts the liquid into an elastic or aeriform fluid, the 

 particles of which, by means of the heat with which 

 they are combined, are made to repel one ano- 

 ther. 



3. Heat must escape from bodies, both in consequence 

 of the attraction of those bodies that have less heat, 

 and the mutual repulsion of the parts of caloric. 

 When the temperature of a body is raised to a cer- 

 tain height, this last cause may operate without the 

 former. On this account, the caloric, in the air 

 is impelled from the radiant body on all sides, 

 and is condensed on the surfaces of the adjacent bo- 

 dies, which, by their attraction, resist its motion. 

 It is probable, that this is effected by undulations, 

 propagated through the caloric fluid. The appa- 

 rent reflection of cold may also receive a solution on 

 this hypothesis. 



4. The production of heat by percussion and friction, 

 is more difficult to be explained on this hypothesis 

 than any of the other phenomena. If we suppose 

 the temperature, or the expansion of a body, to be 

 affected, not merely by the quantity of caloric con- 



VOL. I. Q tained 



