FIELD AND STUDY 



conceivable attraction could result in the organiza- 

 tion of these in a living body. 



Chemical affinity builds up the nitrates, the car- 

 bonates, the hydrates, which in turn build up the 

 living body, but under the control of something 

 more than chemical affinity. Life could not result 

 without chemical affinity, but chemical affinity can- 

 not beget life; at least, it will not in our hands. We 

 have to postulate the organizing impulse — the im- 

 pulse under whose control many units work to- 

 gether to produce one whole, parts subordinated to 

 parts and in which metabolism and reproduction 

 and assimilation take place. 



A rock is also built up of parts,jbut they are parts 

 without function or purposeful relation. Chemical 

 affinity plays its part, but brings* about no change 

 in the behavior or combination of the elements, 

 whereas in a living body a host of* new carbon com- 

 pounds are developed. 



§ 

 One of the strangest things in the world is that 

 though we live all our days in an ocean made up of 

 nitrogen and oxygen, yet one of the most difficult 

 things for us to do is to capture and appropriate any 

 of this nitrogen. We take it into our lungs, it bathes 

 our bodies, in fact we cannot escape from it, and 

 yet to seize it, to separate it frohj the oxygen, and 

 make it unite chemically with some other body and 

 fertilize our soil with it, is an Herculean task. It ia 

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