ABSORPTION OF SALTS BY SOILS. 101 



With the amounts of salts present in the solution employed in 

 this absorption series, and with that already present in the sam- 

 ples, there has been, in every case, a very large removal of lime 

 from the solution, either by direct precipitation, or else by ab- 

 sorption. It can hardly have been thrown out as a sulphate, 

 unless SO 4 already in the soil did the work, because the table 

 shows that but little SO 4 was absorbed, except by the Hagers- 

 town Clay Loam. Four of the soil types actually contributed 

 SO 4 to the solution in the percolation set, as was the case in the 

 other set. In the manure solution series, it will be recalled that 

 there was but a single case where absorption of SO 4 did not take 

 place, while lime went into solution. 



Magnesia was forced into solution from the four Northern 

 soils in both sets of this series, as it was in the manure series ; 

 and it went into solution from the Norfolk Sand in larger 

 amounts in this than in the last series. 



There is no exception, in either set of trials, to notable 

 amounts of nitric acid disappearing from the solution; and 

 here, again, its disappearance cannot be presumed to have re- 

 sulted from denitrification due to biological agencies. 



There appears to have been, in the first set of absorption trials 

 of this series, a recovery of chlorine not shown by an ordinary 

 examination of these soils, and the excess is so large in some 

 -cases that it seems legitimate to assume that absorbed chlorine 

 was forced into the solution. The second set, however, points 

 more strongly to an absorption of chlorine, unless, indeed, the 

 results are admitted to represent irregularities in the method. 



ABSORPTION OF SALTS FROM A PREPARED CHEMICAL SOLUTION 

 BY 8 SOIL TYPES, AFTER HAVING BEEN 11-TIMES WASHED IN 

 DISTILLED WATER. 



After having washed the first series of soils 11 times in dis- 

 tilled water, they were again dried and afterward treated with 

 the Solution whose composition is given in the next table, pre- 

 pared gravimetrically from chemicals in stock. 



This solution was prepared to contain roughly the amounts of 

 the several ingredients in parts per million .that the soil moisture 

 11 



