1917] * SOILS — FERTILIZERS. 809 



"When placed In the cylinders the finer-textured soils showed a lower 

 apparent specific gravity than the coarser, but within groups of somewhat 

 similar texture this value was found to show no direct dependence upon the 

 hygi-oscopicity. 



" The moisture content of the moistened layer, even at the end of the first 

 hour, was only from one-half to two-thirds the maximum water capacity, which 

 shows that the latter has little significance as a direct index of the moisture 

 retentiveness of a soil. The moisture content of the moistened layer fell much 

 more rapidly with the finer-textured soils, at the end of 24 hours it being only 

 between two and three times the hygroscopic coefficient, while in the coarser 

 soils it varied from three to ten times the coefficient. At the end of the five 

 days equilibrium had been practically attained in the finer-textured soils, but 

 in the coarser ones this was far from being the case. The coarser the soil the 

 more slowly was equilibrium reached. 



" The rate of penetration showed little dependence upon the hygroscopicity, 

 but was definitely afi:ected by the moistness, the higher the Initial moisture 

 content of any soil within the limits employed the more rapid being the down- 

 ward movement of water. The distance of penetration during the five days 

 following the application of water increased with the initial moistness of the 

 soil, but was not closely related to the hygroscopicity, owing partly to the 

 slowness with which equilibrium is attained in the coarser soils. 



" With the finer-textured soils the water content of the moistened layer was 

 not distinctly affected by the initial moistness, but with the coarser members 

 the drier the soil the wetter was the moistened layer. Provided that a period 

 of high evaporation is to precede the next rain, the character of the weather 

 immediately following a rain will have a greater effect upon the loss of moisture 

 by evaporation in the case of a coarse than of a fine-textured soil. 



" Glass tubes were filled with the same soils in the same three degrees of 

 moistness and the lower ends placed in contact with water kept at a constant 

 level. The rate of rise during eight or ten days was observed and the moisture 

 in the uppermost layer of the moistened portion of the soil column at the end 

 of this period determined. At first the rise was most rapid in the soils of low 

 hygroscopicity, but the difference gradually lessened until those of intermediate 

 hygroscopicity were in the lead. There was no definite dependence of the rise 

 upon the hygroscopicity. No definite dependence of the rate of rise upon the 

 initial moistness was shown, it being, in the case of the three moisture condi- 

 tions studied, generally most rapid in the moistest condition and slowest in the 

 intermediate. 



•'AH the finer-textured soils showed the highest percentage of moisture at the 

 head of the advancing moist layer when used in the driest condition, but the 

 coarser members showed no difference. The moisture content of this moist 

 layer shows a rather constant relation to both the hygroscopic coefficient and 

 the moisture equivalent, being similar to the moisture retentiveness of the same 

 soils. 



" The relative rates and distances of penetration in the different soils are not 

 similar to the relative rates and heights of capillary rise." 



Orig-in of alkali, R. Stewakt and W. Petebson (C7. S. Dept. Agr., Jour. Agr. 

 Research, 10 (1911), No. 7, pp. SSl-353).— In connection with the authors' well- 

 known studies at the Utah Experiment Station of the origin of niter spots 

 in soils (E. S. R., 36, p. 423), analyses were made of some 400 representative 

 samples of sandstone, shale, " alkali," clay, and an ash consisting of a mixture 

 of dry dust with crystals of " alkali " found just under the clay crust on the 

 most affected parts. 



