86 On the Atomic Theory. 



The pliffiiiomena of the aurora borealis and fierv meteors, in 

 our atmosphere, are occasioned also by electricity 'in the same . 

 way, that is by dislodging combined caloric. 



The heat and light discharged by the electric fluid, particularly 

 by means of friction, confounded philosophers, and led them into 

 many errors, and even to question the materiality of caloric ; at- 

 tnbutmg heat, like gravity, to a mere property of common or solid 

 matter, niferring that it is produced by a peculiar vibration of their 

 particles; and advancing many absurd notions respecting the elec- 

 tric fluid itself. This obscure and far-fetched philosophy, so in- 

 consistent with the simplicity of the laws of nature, appeared to 

 me absurd and chimerical. I have therefore advanced a doctrine 

 which will account for all the phaenomena attendant on electri- 

 city; and which will also tend to establish the materiality of the 

 imponderable elements, and to give them that station among the 

 pcsiderable bodies to which they are entitled; viz. their property 

 of uniting with those bodies, and of dislodging one another from 

 them, according to their different or respective powers. 



Having shown that caloric and the electric fluid are antagonist 

 elements, we shall now consider how far caloric and light agree 

 with each other ; and whether or not there exists any degree of 

 attachment between those subtile elements. From the variety 

 of facts which have been adduced respecting the caloric and 

 light disengaged daring the chemical action of solid substances 

 on each other, and also those evolved from substances by a 

 powerful Voltaic battery, and even by the common process of 

 combustion which takes place constantly before our eyes, — there 

 can be very little doubt but those two elements existed in a la- 

 tent state in those bodies thus acted upon ; and we may also infer 

 that they are constant and inseparable associates. It is true that 

 solid and fixed bodies may be made very hot without the ap- 

 pearance of light; but as they become luminous when their tem- 

 perature is much exalted, no doubt but they contain combined 

 light in their most obscure heat. Some facts which will be re- 

 lated presently, show that these elements may exist in a free and 

 separate state, or nearly so. 



Whenever caloric in a certain degree of concentration is dis- 

 lodged from bodies, no matter how, light is constantly produced. 

 This is a fact which philosophers should attend to. Does light, 

 whose particles are more minute beyond calculation than those 

 of caloric, form atmospheres round the particles of the latter ? 

 If so, are those atmospheres of light, Ijy the concentration of 

 caloric, so diminished by the condensation as to set a portion of 

 it at liberty sufficient to afford illumination ? and again. Do the 

 particles of caloric, when they become less concentrated, or 

 are removed to a certain distance from each other, engage the 



whole 



