116 MICROBES, FERMENTS, AND MOULDS. 



ammoniacal salts, and consequently constitutes a 

 strong manure, very fit to serve as the nutriment of 

 plants. 



This is at once the beginning and the termination 

 of the endless chain which sustains the equilibrium 

 of nature, in which there is no creation, no destruction. 

 Plants draw their nutriment from the soil and the air 

 in the form of mineral solutions, and are devoured 

 by animals or by other parasites ; animals are in their 

 turn devoured by microscopic plants or microbes, and 

 return by means of putrefaction to the condition of 

 mineral salts, which are distributed in the soil, and 

 serve anew for the nutrition of plants. 



We must at the same time be struck by the 

 resemblance which exists between these phenomena 

 of putrid fermentation, and those which occur in the 

 fermentations which accompany the nutrition of 

 animals and plants. Germination and the different 

 digestions which occur in the mouth, the stomach, 

 the intestines, etc., are only fermentations, so that 

 Mitscherlich has paraphrased the Scripture saying, 

 " Dust thou art, and unto dust thou shalt return," 

 by declaring that " Life is only a corruption." 



It should, however, be remembered that fermenta- 

 tions are essentially phenomena of disintegration, 

 which always reduce complex, organic substances to 

 those which are simpler. Plants provided with 

 chlorophyl, on the other hand, alone possess the 

 property of forming higher organic compounds, by 



