98 IIO-\V CROPS FEED. 



is absorbed and decomposed, and a nearly equal volume 

 of oxygen is set free, — consists in the simultaneous deox- 

 idation of c:irl)onic acid and of water, wliereby the former 

 is reduced to carbonic oxide with loss of half its oxygen, 

 and the latter to hydrogen with loss of all its oxygen, viz.: 



Gin-honh ^ Wate - —^ '"Thou I' Hydro- Oxy- 



acld ' oxide yen. yen. 



CO, + l\f> = CO + H, + O, 



In this reaction the oxygen set free is identical in bulk 

 with the carbonic ncid involved, and the residue retained 

 in the plant, COH^, multiplied by 12, would give 12 

 molecules of carbonic oxide and 24 atoms of hydrogen, 

 Avhich, chemically united, might constitute either glucosj 

 or levulose, C,^ 11^^ Oj„, from which by elimination of 

 HjO would result cane sugar and Arabic acid, while sepa- 

 ration of 211^0 would give cellulose and the other mem- 

 bers of its group. 



Whether the real chemical jiroce^^s be this or a different 

 and more complicated one is at present a matter of vague 

 probability. It is, notwithstanding, evident that this re- 

 action expresses one of the principal results of the assim- 

 ilation of Carbon and Hydrogen in the foliage of plants. 



§ 12. 



The following Tabular View may usefully serve the 

 reader as a recapitulation of the chapter now finisheil. 



TABULAR VIEW OF THE RELATIONS OF THE ATMOSPHERIC 

 INGREDIENTS TO THE LIFE OF PLANTS. 



[■ Oxygen, by roots, flowers, ripeiiiuj^ fruit, and by ;ili 

 f^rowiirj.- jiarts. 

 Carbonic Acid, by foliaire and rrreeu parts, but only in 

 j the light. 



Absorbed J Ammonia, us carbonate, by folia<;e, probably at all times. 

 by Pliints. 1 Watek, ax liquid, through the roots. 



Nitrous Aoid (^ united to ammonia, and dissolved in wa' 

 Nitric Aciu ) ter through the roots. 

 Ozone ) 



