134 University of California Publications in Agricultural Sciences [Vol.3 



the soil solution, and of the amounts of each of the solutes contained 

 therein. It renders possible, further, such studies as will clarify our 

 vision with regard to the relations, if any, which obtain between the 

 soil solution and soil extracts as ordinarily made. It permits us for 

 the first time, so far as I am aware, to obtain quickly and directly 

 large portions of the soil solution as it exists naturally under field 

 conditions when crops are growing, and thus to correlate these solu- 

 tions in all their qualities with the conditions of the growing crop. 

 it may doubtless be the means of throwing much light on the methods 

 for making nutrient solutions for growing plants, and probably also 

 on many obscure problems in plant physiological pathology. Indeed, 

 the possibilities are many in which the method which I have described 

 for obtaining the soil solution can be used to the very great advantage 

 of soil and plant studies. 



Transmitted March 8, 1918. 



