AEROSTATICS. 223 



AEROSTATICS. 



SECT. I. 



OF HEAT. 



AN treating of Aeriform Fluids, we begin with the 

 consideration of Heat, which, though it affect all 

 material substances, acts more remarkably on elas- 

 tic fluids than on other bodies. We shall treat of 

 heat as affecting the Bulk, the Fluidity, and the 

 Elasticity of bodies. 



313. HEAT or CALORIC may be regarded as a 

 substance which penetrates and expands all bo- 

 dies, and produces in us the sensation of heat and 

 cold. 



Though we conceive heat to be a substance, it is never 

 found in an independent state, or existing otherwise 

 than as a property of body. 



314. As 



