23 



indeed, need the process of simplification of vegetable 

 food be carried so far as this, in order to arrive at the 

 limit of the plant's thaumaturgy. 



Let water, carbonic acid, and all the other needful 

 constituents, be supplied without ammonia, and an ordi- 

 nary plant, will still be unable to manufacture proto- 

 plasm. Thus the matter of life, so far as we know it 

 (and we have no right to speculate on any other) breaks 

 up in consequence of that continual death which is the 

 condition of its manifesting vitality, into carbonic acid, 

 water, and ammonia, which certainly possess no prop- 

 erties but those of ordinary matter ; and out of these 

 same forms of ordinary matter and from none which 

 are simpler, the vegetable world builds up all the proto- 

 plasm which keeps the animal world agoing. Plants are 

 the accumulators of the power which animals distribute 

 and disperse. 



But it will be observed, that the existence of the mat- 

 ter of life depends on the preexistence of certain com- 

 pounds, namely, carbonic acid, water, and ammonia. 

 Withdraw any one of these three from the world and all 

 vital phenomena come to an end. They are related to 

 the protoplasm of the plant, as the protoplasm of the 

 plant is to that of the animal. Carbon, hydrogen, oxy- 

 gen, and nitrogen are all lifeless bodies. Of these, car- 

 bon and oxygen, unite in certain proportions and under 

 certain conditions, to give rise to carbonic acid ; hydro- 

 gen and oxygen produce water j nitrogen and hydrogen 

 give rise to ammonia. These new compounds, like the 

 elementary bodies of which they are composed, are life- 

 less. But when they are brought together, under certain 



