ORGANIC CHEMISTRY 



development in the work, of organic chemists. As 

 already explained, considerable success has been 

 met with in reproducing the simpler products of 

 nature in the laboratory, but enquiry is now being 

 directed to the methods used by nature in forming 

 these. Not only is very great scientific interest 

 attached to these problems, but the successful 

 solution of some of them might ultimately be of 

 high economic value. For example, a knowledge 

 of the processes followed by the plant in forming 

 a valuable product might enable us to stimulate 

 the production, or perhaps a study of these pro- 

 cesses might lead to an important artificial synthesis 

 of the substance. 



The question of how the plant or animal con- 

 verts the material which it absorbs as food into such 

 a variety of materials is a very complex one. The 

 case of the plant appears to be the simpler, for the 

 organism here deals at the outset with relatively 

 simple materials, carbon being chiefly assimilated 

 through the leaves as carbon dioxide from the 

 atmosphere, whilst nitrogen and phosphorus are 

 taken up through the roots. The conditions of 

 synthesis are very different from those adopted in 

 the laboratory ; for instance, the plant operates 

 at the temperature of the atmosphere whilst the 

 cells of the plant tissue serve as vessels in which 

 the reactions are carried out. 



So far as the assimilation of carbon is concerned, 



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