PART II. 

 BACTERIA IN SOIL AND WATER. 



CHAPTER III. 



THE ORIGIN OF SOIL. 



THE CONTINUATION OF THE FOOD SUPPLY. 



THE farmer's occupation consists in converting soil and air 

 into human food. While his duties seem to be varied they all 

 resolve themselves into extracting from the soil and from the 

 air certain ingredients which are induced to combine into such 

 a form as will serve for food. Whether it be the potatoes 

 that he digs from the ground, the fruit that he plucks from 

 the trees, the wheat that he gathers from the fields, the milk 

 that he draws from the cow, or the flesh that he sends to the 

 butcher, in all cases the product has been enticed by the farmer 

 from mother earth. Chemistry has not advanced to a stage 

 where the elements can be made to combine directly, to 

 produce the materials wanted for food, and the agriculturist, 

 therefore, is obliged to depend upon secondary agents. 

 Throughout nature, life is the agent which he uses for pro- 

 ducing this combination of soil and air into human food. 

 Plant life and animal life both contribute to the process, but it 

 is through life alone that the chemical combinations which re- 

 sult in the production of food are possible. 



The larger part of the material from which food is manu- 

 factured is derived from the inexhaustible supplies in the atmos- 



(53) 



