THEORY OF ASSIMILATION. 157 



resentation of the changes which actually take place in the 

 assimilation of oxygen and hydrogen, it proves conclusively 

 that the vital power is capable of reversing chemical laws. 

 For this process differs entirely from ordinary chemical com- 

 binations ; thus, for example, when carbonic acid, zinc and 

 water are mingled, hydrogen is separated ; but in the process 

 of vegetation, oxygen is separated from the living plant, and 

 given back to the atmosphere. 



In the process of decay, oxygen is returned to the atmos- 

 phere in the form of carbonic acid, and is absorbed from the 

 air to form water ; hence, the process of nutrition and decay 

 are exactly opposite. 



This theory serves rather to illustrate the nature of the 

 changes, than to point out the exact changes which take 

 place. In a similar way, it might be shown what changes 

 may take place, when other substances containing oxygen and 

 hydrogen are taken into the vegetable organs. It is there- 

 effected in assimilation, on the supposition that the carbon is derived 

 from carbonic acid, and the oxygen and hydrogen from the water. 



36 eq. carbonic acid and 36 eq. hydrogen derived > c- 



from 36 eq. vi^ater 5 



with the separation of 72 eq. oxygen. 

 36 eq. carbonic acid and 30 eq. hydrogen de- ) o^ ? 



rived from 30 eq. water \^ = Starch, 



with the separation of 72 eq. oxygen. 

 36 eq. carbonic acid and 16 eq. hydrogen de- > ^ ,, -j 



rived from 16 eq. water \^= Tannic Acid, 



with the separation of 64 eq. oxygen. 

 36 eq. carbonic acid and 18 eq. hydrogen de- ) ^ . • ^ • » 

 rived from 18 eq. water \^= Tartaric Acid, 



with the separation of 45 eq. oxygen. 

 36 eq. carbonic acid and 18 eq. hydrogen de- > ,, ,. ^ ., 

 rived from 18 eq. water ^ = Malic Acid, 



with the separation of 54 eq. oxygen. 

 36 eq. carbonic acid and 24 eq. hydrogen de- > r^i j-^r 



rived from 24 eq. water }^ = Od of Turpentine. 



with the separation of 84 eq. oxygen. 



