LIFE OF THE PLANT-CELL. 85 



two, water and the salts of ammonia, easily enter into a state of decom- 

 position. Water on coming in contact with zinc gives off its hydrogen, 

 and the weakest galvanic current serves to separate its oxygen and hy- 

 drogen ; whilst an alteration of temperature or solution is sufficient to 

 decompose or produce important alterations in the salts of ammonia. 

 Thus, through the destruction of a single equivalent of water, an impulse 

 would be given to an endless chain of chemical processes, which would 

 result in the development of those substances which are found in the 

 plant-cell. The question is, however, still unanswered as to what 

 change is the first that takes place in the series. Liebig has observed, 

 very correctly, that, as far as the ultimate results are concerned, it 

 signifies little whether carbonic acid or water is first decomposed. Al- 

 though, as before stated, we must not explain the changes which take 

 place in the cell on the supposition that the elements, as such, unite 

 together, yet, on the other hand, we are not in a position to say that the 

 formation of starch, &c. is dependent on the decomposition of carbonic 

 acid and water. Where plants grow, and where cells are formed, there 

 we have present at the same time water, carbonic acid, and the com- 

 pounds of ammonia. We also see that nitrogenous and non-nitrogenous 

 substances are developed at the same time, and apparently by the same 

 process. In this point of view, the analogy between the composition of 

 vinegar and the mother of vinegar, which last, according to Mulder, 

 consists of one equivalent of protein and four equivalents of cellulose, 

 is a matter of some interest. Thus : 



C H O N 



74 Water (H O) = . . 74 74 



94 Carbonic acid (C O 2 ) = .94 188 

 2 Carbonate of ammonia 1 , 



(H 2 N 6 CO 2 ) 2 J 



96 76 266 12 

 Forms 



1 Protein = . .48 36 14 12 



4 Cellulose (C 12 H 10 O 10 ) = 48 40 40 



212 Oxygen = . . 212 



96 76 266 12 



The 212 of oxygen would suffice to convert 53 equivalents of alcohol 

 into acetic acid. 



But if we leave out of the question the nitrogenous substances, the 

 following scheme will give us the changes that occur in carbonic acid 

 and water : 



C H O 



12 Carbonic acid = . . 12 24 



24 Water = 24 24 



12 24 48 



24 O = . . 24 



X = . . 12 24 24 



X= 1 Grape Sugar + 12 Water = 12 12 12 -h 12 H O 



{Cellulose ~J 

 Dextrin 1 , 14 }9 1O 



Cane Sugar f + ] 

 Inulin 



1 Wood(Prout)+ 16 =12 8 8 4- 16 HO 



