APPENDIX 



THE PLANT AS A SOURCE OF ENERGY 1 



'Can we really admit that all the sunbeams falling 

 on this our earth are lost without further use, or should 

 we not rather assume that they are but transformed when 

 absorbed by the emerald green of the leaves ? ' 



Scherbin* 



WE all know that if a man is deprived of food he grows lean. 

 This fact is obvious and is understood by everybody, because 

 from the logical point of view it is not difficult to connect these 

 two phenomena, leanness and absence of food. A man's body, 

 like everything else under the sun, becomes wasted ; it uses itself 

 up. This waste is replaced by food. It is not difficult to 

 imagine the food substance transforming itself into the sub- 

 stance of the body, though it will be long ere science arrives at 

 the explanation of all the details of the process. 



Less obvious, though not less known, is the other aspect 

 of the effect of food, another side of its influence upon our 

 organism. \^ant or insufficiency of food causes loss of energy. 

 A man or an animal when hungry grows weak. Food restores 

 strength. The more work is done by an organism, the more 

 food is required. Everybody knows that when a horse is 

 expected to do hard work it receives an extra portion of oats 

 to help it to do that work. This fact is universally known, 

 and yet reflection alone is not sufficient to explain it. 



1 Public lecture delivered before the Technical Society in St. Petersburg 

 in 1875. 



2 These lines of our talented Russian poet may justly excite our wonder 

 if we consider that at the time they were written all the botanists, hav- 

 ing lost sight of Senebier's remarkable intuitions, did not even suspect 

 the existence of Robert Mayer's great generalisations, 



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