IN THE VEGETABLE KINGDOM. 199 



of these substances, they do not afford the slightest explanation of 

 their mode of origin. Mulder does, indeed, conjecture, from the 

 more abundant occurrence of these substances in the cells at the 

 apices of the roots, that they are formed here from the ammoniacal 

 compounds of the hurnus acids (as they are conversely decom- 

 posed into these acids and ammonia by the action of concentrated 

 hydrochloric acid) ; but even if it be granted that the ammoniacal 

 salts reach the plant only or principally through the roots, and if, 

 further, it be shown that many of these absorbed substances 

 undergo chemical metamorphoses in the fibrils of the roots, the 

 frequent occurrence of ammoniacal salts in the rising sap of the 

 plant seems rather to prove that their metamorphosis must be 

 effected at some other point. It is not improbable that the 

 protein-bodies are principally formed wherever the process of 

 reduction is most practicable, as, for instance, in the leaves. On 

 the one hand, we know that all protein-bodies, and especially those 

 obtained from the vegetable kingdom, contain a considerable 

 quantity of sulphur; and, on the other hand, we learn from 

 E. WolfPs* carefully conducted ash-analyses of the different com- 

 ponent parts of plants, that the sulphates, as already observed, are 

 accumulated in early spring in the buds and leaves, whilst they 

 disappeared from all other parts of the plant; and that the 

 quantity in which they occur in these parts is too large to admit of 

 the supposition that they are derived from the protein-substances 

 already present in the leaves ; we are, therefore, naturally led to 

 the idea that the sulphates must be already accumulated in the 

 leaves at a very early period, and that they undergo only a gradual 

 reduction in order to be applied to the formation of albuminous 

 substances in proportion to the quantity of ammonia with which 

 the plant is supplied. We can hardly refer the deoxidation of the 

 sulphates to any part of the plant except the leaves, and, on this 

 account, we may assume that these organs afford the final stimulus 

 required for the complete development of these salts. If it would 

 not be carrying us too far into the region of conjecture, we might 

 hazard the remark that as the alkaline carbonates contribute to 

 the formation of non-nitrogenous bodies, the sulphates and 

 phosphates may also take an important share in the formation of 

 protein-bodies, such a conjecture deriving plausibility from the 

 simultaneous occurrence of phosphates in all those vegetable 

 organs which are rich in protein-bodies, and from the generally 



* Journ. f. pr. Chem. Bd. 51, S. 1-82. 



