Steam Sterilization u.n Water-Suluble AIattlr in Soils. 267 



In the steamed soil on which the wheat was grown the amount of 

 total soluble matter has increased, as was the case in the experiment 

 of which the results are given in Table VII. In the steamed soil to 

 which an infusion of unsteamed soil was added the increase in soluble 

 matter is very slight. As was to be expected, the soluble matter in 

 the unsteamed soils decreased in the cropped soil. 



Fig. 76. — Effect of adding an injuaion oj iinilerilized soil io a slerilized soil 

 as indicated by a crop of millet following wheat, no further treatment having been 

 given tlie soil after the wheat was removed 



Pot J I — Soil No. 5 untreated 

 Pot J5 — Soil Xo. 5 sterilized 



Pot ')4 — Soil Xo. 5 sterilized and treated with an infusion of the 

 same soil not sterilized 



It will be noticed that the percentage of inorganic matter in both 

 of the steamed soils has been decreased by cro[)i)ing, while in the un- 

 steamed soil it has been increased. This indicates either that the 



