NEW CONCEPTIONS IN SCIENCE 



each year more than he receives soon closes his 

 doors. 



A line of delicate experiments revealed to M. 

 Berthelot that the fixation of nitrogen is incon- 

 testably due to the presence of microbes. His work 

 he summed up in an expressive phrase. "The 

 soil," he said, " is in some sense living." This idea, 

 taken up by some German experimenters, has led 

 to the establishment of microbe cultures, for the 

 breeding and sale of the especial family of germs 

 which perform this useful work. 



But M. Berthelot, not content, has gone further 

 and shown that, under the influence of a silent 

 discharge of electricity, many organic compounds 

 may absorb the nitrogen of the air. So a series of 

 lightning-rods leading to large metal plates buried 

 in the ground markedly increase the yield of a field. 

 The influence of the nitrates used directly as fer- 

 tilizers is so evidently beneficial that with the 

 development of the guano beds of Chili a great 

 industry has grown up. Still, the nitrates are 

 dear, the beds not extensive. Taking up an old 

 experiment of Cavendish, M. Berthelot has shown 

 that under the action of a high-tension current of 

 electricity the nitrogen and oxygen of the air may 

 be made to combine in large quantities. Much, 

 indeed, of his chief work has been done with this 

 puissant aid. He was the first to show the role 



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