126 



to analysis, 2.7504 grams, equal to 2750.4 parts per million of 

 the K 2 O, this having occurred at the end of two days. At this 

 time 250 c. c, of solution were removed and 2250 c. c. of water 

 put in its place, when it was vigorously shaken and allowed to 

 stand two more days. At the end of this time 1500 c, c. of solu- 

 tion were removed and as much more water added, the operation 

 being repeated 8 times, making determinations on each portion 

 of solution removed. 



The results stand as given in the next table: 



Amounts of potash redissolved after absorption by a soil. 



In parts per million. 



It is seen from the last column of this table that, from! the 

 standpoint of the amounts of potash usually found in soil mois- 

 ture, a large amount was still recovered by the 10th digestion, 

 equal to nearly 55 parts per million of dry soil, which is more 

 than double that usually recovereed by single short period wash- 

 ings. Moreover, after the se<x>nd, until the 10th, the amounts 

 of potash redissolved each time by the water were about the 

 same, or about 77 parts per million of soil as an average. 



In addition to the experiments cited, relative to the recovery 

 of potash from soils, after absorption, Peters compared the ef- 

 fects of carbonic acid and weak solutions of acetic and hydro- 

 chloric acid. The results of these observations are brought to- 

 gether in the next table. 



