MOVK.MKNTS ()I SALTS IN SOILS. 93 



MOVEMENT <>I CHLORIDES BY CAPILLARITY. 



Xo salt in the series investigated moves with such apparent 

 freedom and abandons the soil so completely as do the chlorides, 

 or, at least, as does the chlorine. 



The most striking feature in the tables of data presented in 

 this series of observations is the completeness with which the 

 chlorine has disappeared from all but the surface inch of soil, 

 in four of the types under treatment, even at the end of 20 days. 

 This statement applies with entire fullness to the two Janes- 

 ville soils and to the Norfolk Sandy Soil and the Xorfolk Sand. 

 With the Selma Silti Loam, the Sassafras Sandy Loam and the 

 two Hagerstown Loams, the chlorine was not completely forced 

 into the upper layer, but well up toward it. 



Another point, to which special attention should be directed, 

 is the fact that the absolute amount of chlorine recovered at the 

 end of 50 days is greater than that which is recovered at the 

 end of 20 days. This is doubtless partly due to the fact that 

 the zeros in the table must be understood to mean amounts too 

 small to measure by the method rather than no chlorine present, 

 and the more complete capillary sweeping results in concentrat- 

 ing the chlorine until the quantities become large enough to be 

 determined. 



There is stall another feature of these chlorine data which 

 calls for an explanation and this is the reduction of the chlorine 

 in the solution added to the soil, which contained 25 to 30 parts 

 per million, to so small an amount as to fall below the limits 

 of the method. It must be understood that: the Hagerstown 

 Loam, for example, carried in the lower two inches of soil, 30 

 per cent, of its dry weight of the solution, which contained not 

 less than 24 parts per million when it entered the soil. This is 

 enough to represent 7.2 parts per million of the dry soil could 

 it. all be recovered by the method of washing used. Moreover, 

 it is true, in most cases, that the absolute amounts of chlorine 

 recovered from the soils are nearly equal to, or even greater, 

 than the amounts called for by the known amounts added to the 

 soils with the solution plus the measured amounts in the soils 

 before the solution was added. 

 7 



