Lesson xxvm.] F'RE* 179 



afford us : let us suppose, I say, that in such a 

 situation we received information that a person had 

 invented something by the help of which all these 

 defects and wants might be supplied : I would only 

 ask, if we should not, under such circumstances, 

 entertain very high ideas of the wisdom of the 

 inventor ? 



The ingenious young reader will know how to 

 apply this conjecture and question, without any 

 farther comment upon them. 



By Fire is here to be understood, that subtile in- 

 visible cause by which bodies are made hot to the 

 touch, and expanded or enlarged in bulk ; by which 

 fluids are rarefied into vapour; or solid bodies be- 

 come fluid, and at last either dissipated and carried 

 off in vapour, or else melted into glass. It seems 

 also to be the chief agent in nature, on which 

 animal and vegetable life have an immediate de- 

 pendence. 



Among philosophers, Fire is now usually de- 

 nominated CALOKIC, which appears to be a highly 

 elastic and imponderable substance ; and it is so 

 very subtile, that neither has its gravity been yet 

 ascertained, nor its existence, in a simple and 

 uncombined state, been shewn. There can be very 1 

 little doubt that it radiates with light from the 

 sun : and experiments shew, that, like light, its 

 absorption is affected by the difference of colour 

 and of surface possessed by different bodies. It 

 combines chemically with all bodies, in a quantity 

 proportioned to their affinity with it. By its elastic 

 power, or power of repulsion, it constantly tends 



to 



