340 



now CROPS FEED. 



and this process was repeated ten times, 

 thus in the several washin<?s as follows : 



The soil lost 



In 2d, 

 0.0075 



3d, 

 0.0096 



4th, 

 0.0082 

 In 8th, 

 0.0112 



5th. 

 0.00G9 



nth, 



0.0201 



6th, 7th extract. 



0.0075 0.0082 grams. 



10th extract. 

 0.083 irrams. 



Removed in all, 0.0875 gram of i)otash. 

 Remained in soil, 0.1239 gram. 



In these experiments one part of absorbed potash re- 

 quired 28,100 parts of water for solution. 



Similnr results were obtained by Ilenneberg and Stoh- 

 mann with a soil wliich had absorbed ammonia; one part 

 of this base required 10,000 parts of water for re-solution. 



It has been already stated, that the ahsorption of one 

 base is accompanied In/ the liberation of a corresponding 

 quantity of other bases, while the acid element, if it be 

 sulphinic or nitrii acid, or cJdorine, is found in its 

 original quantity in the solnt'on. As an illustration of 

 this rule, the following data obtained by Weinhold in the 

 treatment of a soil witli sulphate of ammonia are ad- 

 duced. The quantities are expressed in grnms, except 

 where otherwise stated. 



Content of Sohition 



We observe that the soil not only retained no sulphuric 

 acid, but gave up a small quantity to the solution. Of 

 the ammonia a little more than one-half in one case, and 

 three-eighths in the other, was absorbed, and in the solu- 

 tion its place was supplied chiefly by lime, but to some 

 extent also by potash, soda, and magnesi.i, which were 

 dissolved from the soil. It is also to be noticed that in 

 the two cases — unlike quantities of the same soil aud 



