nv H. GRKIG-SMITH. 



G93 



Experiment xvi. 



As there could be no pliagocytes present in the pasteurised 

 soil, and since it has been shown (pp. 682-684) that ether has 

 no action upon the soil-toxin, the increased growth from the 

 ether-treatment can be ascribed only to the increased solu- 

 bility of the nutrients, resulting from the segregation of the 

 agricere. 



The action of the fat-solvent was again tested upon two 

 soils, which had been obtained from the Hawkesbury Agri- 

 cultural College. They were designated "good" and 

 "medium." After being moistened with water, they were 

 heated in an air-oven, as in the previous experiment. The 

 temperatures in the middle of the soils reached 75° in an 

 hour, and was 79° ten minutes later. The top layers were 

 rejected, and the soils were spread out to cool and dry. 



With regard to the soil-bacteria, 20 gr. portions of the 

 soils were, after treatment, moistened with sterile water, and 



