1 16 BACTERIOLOGY. 



of many poor soils may be considerably in- 

 creased without the application of manure. In 

 Germany Schulz has accomplished this profit- 

 ably with the use of lupine. In order to main- 

 tain the existence of those plants which are not 

 possessed of such direct bacterial assistance, 

 nitrogen in the form of saltpeter must be ar- 

 tificially added to the soil, or else we must sup- 

 ply manures rich in organic substances and 

 out of which ammonia can be produced by bac- 

 terial decomposition, the ammonia being in 

 turn oxidized to saltpeter in the soil by the 

 nitrifying organisms. 



When ordinary organic substances are decom- 

 posed, several species of microbes generally 

 take part in the process, some species working 

 together and simultaneously. This cooperative 

 activity is called symbiosis. In the process of 

 sake manufacture in Japan, a mould, Aspergil- 

 IMS Oryzcz, first inverts or converts to sugar the 

 starch of the cooked rice, and out of this 

 sugar a species of bacterium then forms lactic 

 acid and a yeast alcohol. According to Juhler 

 this yeast is perhaps only a yeast form belong- 

 ing to the Aspergillus itself and not another 

 species. In the manufacture of arrack in Java 

 and sake in China, a species of Mucor, accord- 

 ing to Eijkmann, furnishes the invert ferment, 

 while the fermentation of the molasses is 



