MECHANISM OF NATURE 



to heat and magnetism ; every substance is playing 

 a part in the economy of nature. 



Is it dead matter that exercises attraction upon 

 other dead matter ? Then is force an occult power, 

 and all science guesswork of to-day, to be over- 

 thrown to-morrow by the last discovered occult 

 power ? 



There is something going on in bodies changing 

 through force, beside a mere widening and closing 

 of interstices between particles. (Prop. XVII, 

 B.I.) 



But in all those manifestations of force, where 

 our reason can clearly, even if not directly through 

 the medium of our senses, perceive a movement of 

 P. S. from one body to another, we yet fail utterly 

 to observe a diminution of mass in one and an in- 

 crease in the other. The mere passage of void mat- 

 ter through two organized bodies cannot produce 

 that inequality between them which is necessary 

 to a display of force. Somehow the void matter 

 must take hold of both bodies, and of each differ- 

 ently. There seems then no other hypothesis, ex- 

 cept in those forces at least that have a strict rela- 

 tion to mass, that the whole mass is subject to a 

 fundamental law of life. And the constant ex- 

 change of material, which we observe in complex 

 identities, must extend to all organized matter. 



Let it be granted that atoms as well as the most 

 complex identity must continually exchange their 

 component parts. 



Then the question presents itself, does the whole 

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