PT. iir. OR POISONED BY VEGETABLE GROAVTII ? 141 



grow in particular soils is tlie absence of the particular 

 inorganic matters adapted to their pecuhar constitution ; 

 and that the reason why particular plants cease to grow 

 on particular lands is their having taken up those 

 peculiar inorganic constituents necessary to them, and 

 these being together with the crop abstracted from the 

 soil by man — not their having deposited a suicidal 

 poison from their roots, and thus forming cases of 

 vegetable 'felo de se.' 



The organs of absorption of the roots of wheat, 

 beans, potatoes, turnips, or mangold wurzel, cabbage, 

 and lucern, sainfoin, or the common grasses, probably 

 differ as much as the internal and external structure of 

 the roots and plants ; and, besides, searching for their 

 inorganic constituents at different levels in the soil, 

 they may probably be only capable of taking up those 

 adapted to their peculiar constitution.* 



That the proper juices, the various peculiar acids, 

 and the organic salts, found as carbonates in the ashes 

 of plants, and formed by the combination of the alkaline 

 bases, potash, soda, hme, magnesia, with the peculiar 

 organic acids of plants, play an essential part in the 

 functions and development of the different parts of 



* We don't know wlietlier roots have the power of selection 

 or not ; and, in reference to this all-important first principle of 

 vegetable physiology, Liebig flatly contradicts himself. Page 92 

 he writes : ' All substances in solution in a soil are absorbed by 

 the roots of plants, exactly as a sponge imbibes a liquid and all 

 that it contains without selection.' Page 101 he writes: ' When 

 roots find their more appropriate base in sufficient quantity, they 

 will take up less of another.' 



