MATTER, LIVING FORCE AND HEAT. 1 3 



deranged, nothing ever lost, but the entire machinery, 

 complicated as it is, works smoothly and harmoniously. 

 And though, as in the awful vision of Ezekiel, ' wheel may 

 be in the middle of wheel,' and every thing may appear 

 complicated and involved in the apparent confusion and 

 intricacy of an almost endless variety of causes, effects, 

 conversions, and arrangements, yet is the most perfect 

 regularity preserved — the whole being governed by the 

 sovereign will of God. 



" A few words may be said, in conclusion, with respect 

 to the real nature of heat. The most prevalent opinion, until 

 of late, has been that it is a substance possessing, like all 

 other matter, impenetrability and extension. We have, 

 however, shown that heat can be converted into living 

 force and into attraction through space. It is perfectly 

 clear, therefore, that unless matter can be converted into 

 attraction through space, which is too absurd an idea to 

 be entertained for a moment, the hypothesis of heat being 

 a substance must fall to the ground. Heat must therefore 

 consist of either living force or of attraction through space. 

 In the former case we can conceive the constituent particles 

 of heated bodies to be, either in whole or in part, in a state 

 of motion. In the latter we may suppose the particles to 

 be removed by the process of heating, so as to exert 

 attraction through greater space. I am inclined to believe 

 that both of these hypotheses will be found to hold good, — 

 that in some instances, particularly in the case of sensible 

 heat, or such as is indicated by the thermometer, heat will 

 be found to consist in the living force of the particles of 

 the bodies in which it is induced ; whilst in others, 

 particularly in the case of latent heat, the phenomena are 

 produced by the separation of particle from particle, so as 



