NOTES AND ABSTRACTS. 



275 



gives, first, a summary of the results obtained by other scientific 

 investigators into this subject, and concludes with an account of the 

 experiments carried on in the laboratory of the Department of 

 Agriculture at Washington. 



The subject is important in view of practical soil work, the 

 manufacture of fertilizers, and for various technical processes. The ' 

 principal object of the work has been to determine how absorption 

 controls the concentration of the soil solution, which is the 

 great nutrient medium upon which plants feed, and, further, 

 to determine its effect upon the structure of the solid portion 

 of the soil in modifying its power to hold and maintain the 

 soil solution for the continued use of the plant. It has been shown 

 that a number of modifying factors enter into each particular case, 

 which make it impracticable to formulate a simple general law which 

 will account quantitatively for the distribution of a dissolved substance 

 between the liquid solution and the absorbing medium. The nature 

 of these modifying factors has been the subject of careful investigation, 

 the results of which are here recorded. The most important of these 

 factors is the change in the physical character of the soil itself conse- 

 quent upon the absorption of the dissolved materials, which change, 

 in turn, influences the drainage condition, the aeration of the soil, its 

 capacity to hold the soil solution and control its movement through 

 the soil, the composition of the soil solution, and the character and 

 rate of the chemical changes taking place in the soil solution. 



In order to bring out clearly the general application of the pheno- 

 mena of absorption and the general principles derived therefrom, a 

 number of solvents (or pure liquids used to dissolve some solid, liquid, 

 or gas), of solutes (or the substances dissolved by the solvent), and of 

 absorbents, in addition to soils and constituents of the soil solution, 

 have been studied. 



The establishment of these general phenomena, in the case of 

 pure substances where no life processes enter, strengthens very greatly 

 the certainty in their validity when they are found to hold good for 

 such very complex materials as exist in soils and soil solutions. 



The bulletin gives tables of statistical results of successive soil 

 analyses and descriptions of the apparatus and methods employed by 

 different investigators. — M. L. H. 



Soy Beans. By 0. V. Piper and H. T. Nielsen (U.>S'. A. Dep. Agr., 

 Faryn. Bull 372 ; October 1909 ; 6 figs.).— The bulletin, after describing 

 the plant and its culture, deals with the importance of the soy bean 

 as a forage crop and the food value of the meal for dairy cows. " In 

 the trial for the comparison of soy-bean meal and cotton-seed meal 

 the yield both of milk and butter fat was about 5 per cent, greater for 

 soy-bean meal. " — V. G. J. 



Soy Bean (a Comparison with the Cow Pea). By Ohas. A. 

 Mooers {U.S.A. Exp. Stn. Tennessee, Bull. 82, Dec. 1908).— The 



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