50 INDUCTION. 



perceptible portion of the water contains both those 

 substances, portions of hydrogen and oxygen smaller 

 than the smallest perceptible must have come toge- 

 ther in every such minute portion of space ; must 

 have come closer together than when the gases were 

 in a state of mechanical mixture, since (to mention 

 no other reasons) the water occupies far less space 

 than the gases. Now, as we cannot see this contact 

 or close approach of the minute particles, we cannot 

 observe with what circumstances it is attended, or 

 according to what laws it produces its effects. The 

 production of water, that is, of the sensible pheno- 

 mena which characterize the compound, may be a 

 very remote effect of those laws. There may be 

 innumerable intervening links ; and we are sure that 

 there must be some. Having full proof that corpus- 

 cular action of some kind takes place previous to any 

 of the great transformations in the sensible properties 

 of substances, we can have no doubt that the laws of 

 chemical action, as at present known, are not ultimate 

 but derivative laws ; however ignorant we may be, and 

 even though we should for ever remain ignorant, of 

 the nature of the laws of corpuscular action from 

 which they are derived. 



In like manner, all the processes of vegetative 

 life, whether in the vegetable properly so called or in 

 the animal body, are corpuscular processes. Nutrition 

 is the addition of particles to one another, in part 

 replacing other particles separated and excreted, in 

 part occasioning an increase of bulk or weight, so 

 gradual, that only after a long continuance does it 

 become perceptible. Various organs, by means of 

 peculiar vessels, secrete from the blood, fluids, the 

 component particles of which must have been in the 

 blood, but which differ from it most widely both in 



