720 



STATE BOARD OF AGRICULTURE. 



I lie liduid. Now tlic soils ;ire iiol dcliiiiU' coiiipuiiuds and the tj[uestioii 

 i ises, is their !?olul)ility dependeut or independent of the relative masses 

 of the solid and the liquid. 



It was with the object of obtaining definite information upon this 

 important point that the present investigation was undertaken. Inci- 

 dentally, this information, it was thought, would throw further light 

 upon the subject as to whether or no the solubility of the soils employed 

 in the preceding researches has attained equilibrium. This study con- 

 sisted of placing 5 grams of air-dry soil in the freezing point tubes, wash- 

 ing it several times by decantation and then adding to it sufficient water 

 to bring its water content to the ration of about 1 of soil to about 5 of 

 water. The mixture was maintained at room temperature and the freez- 

 ing point depression determined in the usual way. The data obtained 

 are shown in table 26. In order to ascertain the specific effect of the 

 relative masses of soil and water upon the solubility, the results of the 

 above table must be compared with the results of table 22 where tlie 

 ratio of soil to water was 1 to .7. For convenience and immediate 

 reference the soils in both tables are given the same numbers. 



TABLE 26.— RATE AND EXTENT OF SOLUBILITY OF NATURAL SOILS IN DISTILLED 

 WATER WHEN THE RATIO OF SOILS TO WATER IS ABOUT 1 TO 5 AND MIXTURE 

 MAINTAINED AT ROOM TEMPERATURE. FIGURES REPRESENT FREEZING POINT 

 DEPRESSION. 



Days. 



1 

 4 

 8 

 9 

 11 

 12 



14 

 19 

 31 

 26 



Wisconsin Superior clay 



Georgia Cecil clay 



Micnigan clay loam 



Michigan tlay loam 



Micnigan dark brown silt loam. . . 

 Michigan dark brown silt loam. . . 

 Michigan dark brown silt loam 



Wisconsin Miami silt loam 



Mississippi Memphis silt loam. . . . 



Michigan fine sandy loam 



California Okley fine sandy loam . 

 Michigan fine sand 







C° 



.005 



.005 



.005 



.005 



.005 



.005 



.005 



.005 



.005 



.005 



.005 



.004 



C° 



.007 



.007 



.007 



.007 



.007 



.007 



.007 



.007 



.005 



.007 



.OOG 



.004 



C° 



.013 



.010 



.013 



.018 



.016 



.016 



.012 



.016 



.008 



.010 



.010 



.004 



C° 



.012 



.009 



.016 



.018 



.018 



.018 



.014 



.015 



.009 



■ OK) 



.009 



.004 



16 



C° 



.013 



.010 



.016 



.020 



.020 



.020 



.014 



.016 



.OOG 



010 

 .009 

 .005 



23 



C° 

 .012 

 .010 



.018 

 .021 

 .022 

 .020 

 .014 

 .019 

 .010 

 .012 

 .009 

 .005 



32 



C° 

 .014 

 .011 

 .018 

 .026 

 .028 

 .020 

 .018 

 .018 

 .010 

 .013 

 .009 

 .004 



41 



.013 

 .010 

 .018 

 .026 

 .02? 

 .020 

 .020 

 .020 

 .011 

 .012 

 .010 

 .005 



53 



C° 

 .014 

 .012 

 .020 

 .027 

 .027 

 .022 

 .020 

 .020 

 .010 

 .013 

 .010 

 .008 



63 



C° 



.014 



.011 



.020 



.028 



.027 



.024 



.021 



.019 



.012 



.013 



.011 



.007 



A comparison of the above data with the corresponding data in table 

 22 reveals at once the important fact that when the ratio of soil to water 

 is 1 to 5 the solubility is much smaller than that when the ratio of soil 

 to water is 1 to .7. Indeed, in the majority of the soils the magnitude 

 is only half as large at the ratio of 1 to 5 as it is at the ration of 1 to ,7. 

 Thus at the end of 63 days the depression at the two ratios is as follows 

 for the various corresponding soils : 



Eatio — 

 1:5 .014° .011° .020° .028° .027° .024° .010° .012 .013° .011° .007° C. 



