30 THE PAST CONDITION 



substance by a peculiar combination of matters belong- 

 ing entirely to the inorganic world ; that, then, the 

 animal was constantly appropriating the nitrogenous 

 matters of the plant to its own nourishment, and re 

 turning them back to the inorganic world, in what we 

 spoke of as its waste; and that, finally, when the 

 animal ceased to exist, the constituents of its body 

 were dissolved and transmitted to that inorganic world 

 whence they had been at first abstracted. Thus we 

 saw in both the blade of grass and the horse but the 

 same elements differently combined and arranged. We 

 discovered a continual circulation going on, — the plant 

 drawing in the elements of inorganic nature and com- 

 bining them into food for the animal creation ; the ani- 

 mal borrowing from the plant the matter for its own 

 support, giving off during its life products which re- 

 turned immediately to the inorganic world ; and that, 

 eventually, the constituent materials of the whole struc- 

 ture of both animals and plants were thus returned to 

 their original source : there was a constant passage 

 from one state of existence to another, and a returning 

 back again. 



Lastly, when we endeavoured to form some notion 

 of the nature of the forces exercised by living beings, 

 we discovered that they — if not capable of being sub- 

 jected to the same minute analysis as the constituents 

 of those beings themselves — that they were correlative 

 with — that they were the equivalents of the forces of 

 inorganic nature — that there were, in the sense in 

 which the term is now used, convertible with them. 

 That was our general result. 



And now, leaving the Present, I must endeavour 

 in the same manner to put before you the facts that 



