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peiided in the atmosphere, it cannot be 

 said to ascend more than to descend ; and 

 the physiologist forgets that rain descends. 

 But I do not think that M. Bonnet's facts 

 are more to be depended on than his 

 reasoning. He states, that if leaves are 

 floated on water on their upper surfaces 

 they will die as soon as if they were not 

 put in water, but if they are floated on 

 their lower surfaces they will remain alive 

 as long as if their stalks were immersed in 

 water, I tried this experiment in 1836, 

 and found that the leaves floated on their 

 upper surfaces remained alive as long, or 

 rather longer, than those on their lower 

 surfaces ; one remained in part alive for 

 six weeks. I have only had opportunity of 

 seeing these theories of M. Bonnet quoted. 



According to this class of physiologists, 

 of which the great chemist Liebig is the 

 modern oracle, when trees are in full leaf 

 they receive their entire nutriment through 

 their leaves from the atmosphere, and "the 



