HYPOTHESES OF NEWTON. 275 



The power of generalization by which he traced 

 remote analogies, and reduced a vast multitude 

 of apparently opposite phenomena to the domi- 

 nion of one law, displayed an admirable faith in 

 the uniformity of nature. Yet the projectile force, 

 the vacuum of space, and the vis insita which he 

 represents as the cause of attraction and repul- 

 sion, were mere -hypotheses, wholly unsupported 

 by evidence. And that the illustrious author 

 himself was fully convinced of this during the 

 latter period of his life, is manifest from the 

 whole tenor of his speculations concerning the 

 aether, which, as I have already shewn, he finally 

 regarded as the primary physical cause of cohe- 

 sion, capillary attraction, and of gravitation ; but 

 without explaining how it produces the repulsion 

 of atoms, and the centrifugal force of the heavenly 

 bodies ; or in what way the phenomena of chem- 

 istry, geology, meteorology, and planetary mo- 

 tion, are connected with the influence of the im- 

 ponderables, and the relations of the latter to 

 each other. 



But in the total absence of caloric, if such a 

 thing were possible, the whole material universe 

 would disappear no less completely than if anni- 

 hilated : for it is obvious that in their separate 

 state, the chemical atoms of ponderable matter 

 could not be recognized by the senses. And I 

 have proved that caloric is the organizing prin- 

 ciple by which they are aggregated into visible 



