INCREASE OF CARBON IN SOILS. 1 29 



stated, $. 119) a considerable amount of matter, formed in the 

 vegetable itself, and corresponding in character with its peculiar 

 secretions ; and this gradually undergoes decomposition, furnish- 

 ing a large proportion of carbon. The leaves of plants which 

 fall in the forest in autumn, and the old roots of grass in the 

 meadow, are likewise converted into a rich vegetable mould, 

 capable of yielding a large supply of carbonic acid ; and thus it 

 becomes evident, that plants must absolutely derive more carbon 

 from the atmosphere, than they fix in their own tissues, since 

 they are continually increasing the amount of vegetable mould 

 on the surface of the earth. 



187. Thus we perceive, that no matter which has been 

 organised, can serve as the food of Plants, until it has undergone 

 decomposition ; and that it is solely in the constant and regular 

 supply of carbonic acid it affords, that vegetable mould is more 

 adapted for the support of vegetable life, than any other kind of 

 soil. If we could form a soil of mineral substances only, in 

 every portion of which carbonic acid should be slowly liberated, 

 and which would be equally fit in other respects, Plants would 

 flourish quite as well in it. And thus we see a very important 

 difference in the characters of the Animal and Vegetable King- 

 dom ; for, whilst the beings of the first group are entirely 

 dependent for their nourishment, upon matter that has been pre- 

 viously organised, and thus derive their support either from ani- 

 mal or vegetable bodies, those of the latter are dependent for 

 their growth, only upon the materials supplied by the inorganic 

 world, although their increase may be advantageously assisted 

 and stimulated, by those which they derive from the decay of the 

 former. 



188. And here again do we trace a beautiful harmony, be- 

 tween the various parts of the grand scheme of Creation ; for had 

 Vegetables been dependent, like Animals, upon organic matter, 

 both classes of beings must have gradually disappeared from the 

 face of the earth, since the spontaneous death and decay of a 

 large proportion of them, is constantly restoring to the inorganic 

 world, the elements they have for a time held, in those peculiar 

 forms of combination which are termed organic ; and thus the 



