SCIIULTZENSTEIN — NUTRITIVE CONSTITUENTS OF WATER. 121 



originally at the creation there was no carbon in the soil, but 

 merely carbonic acid in the air, and the humus arose at a later 

 period from the decomposition of carbonic acid by means of plants. 

 These suppositions, however, are quite erroneous. We find even 

 in the primitive mountains carbon in the form of bituminous mix- 

 tures, as in bituminous talc, basalt, and lava, which contain 3 per 

 cent, of inflammable constituents ; and although coal was in the 

 first instance a result of vegetation, there are in its neighbour- 

 hood, in all mountain formations, rocks containing carbon, whose 

 bituminous constituents, being soluble in water, can serve for 

 the nutriment of plants. Coal, moreover, as stated above, could 

 not be formed of carbon and water, since it contains totally dif- 

 ferent proportions of oxygen and hydrogen from those which exist 

 in water, and, moreover, much nitrogenous admixture whose pre- 

 sence is quite inexplicable on the carbonic-acid theory. On 

 the other hand, water, after long contact, dissolves even out 

 of the hardest bituminous rocks carbonic constituents, which 

 in this form may be absorbed by plants. The more barren soil 

 may be rendered fruitful by means of such water laden with 

 nutritious particles, when it springs up from below. In this way 

 it is also possible that, without any carbonic acid from the air, a 

 sterile sand may acquire a coating of humits from a vegetable 

 growth, induced by the surface-water, as the plants which have 

 thus generated decay in the lapse of generations and increase the 

 formation of mould. This can arise only from the fact that water 

 is the medium of nutriment. The carbon of plants comes, then, 

 from the ground, and not from the air. So it is in our modern 

 world ; and there is nothing to prevent its having been so in the 

 ancient world. This truth must give a more natural direction to 

 the theory and practice of cultivation. 



Nitrogen plays an important part in the nourishment of 

 flowering-plants, with which the influence of animal manure on 

 the cultivation of flowers and fruits is intimately connected. 

 Saussure, who made the discovery that rain-water contains a small 

 quantity of carbonate of ammonia, expressed an opinion that the 

 nitrogen of plants might be derived from the air in the form of 

 carbonate of ammonia, that this substance might be developed from 

 animal matters by putrescence and so dispersed in the air, and 

 that manure decomposed entirely into carbonate of ammonia and 

 carbonic acid. The quantity of carbonate of ammonia which is 

 brought down by the rain from the air is, however, so small, that 

 a hogshead of rain-water contains barely ^ gr. ; while, on the other 



