338 HOW CKOPS FEED. 



ments, 100 grms. of soil absorbed from 250 cubic centi- 

 meters of solutions of chloride of potassium of various 

 degrees of concentration, as follows: 



strength of Solution. Pota-ih absorbed by 



Designa- Quantity of potash in ^0 c.c. 100 parts By lO.OOO parts in ProjMrtion 



tion. of solution. of soil, round numbers. absorber/ 



|g„ equiv. = 0.1472 gram. 0.9S88 gram. 10 ^i^ 



\ta " — 0.2944 " O.iaSl '• 14 Mo 



a, " = 0.5888 " 0.1990 " 20 ' I3 



1,0 " - 1.17-7 " 0..3124 " 31 'U 



U " = 2.3555 " 0.4503 " 45 ' U 



A glance at the right-hand column shows that although 

 absolutely less potash is absorbed from a weak solution 

 than from a strong one, yet the weak solutions yield 

 relatively more than those wiiich are concentrated. 



The quantity of base absorbed in a given time, also de- 

 pends upon the relative mass of the solution and soil. In 

 these experiments Peters treated a soil with various bulks 

 of ' |„ solution of chloride of potassium. The results are 

 subjoined : — 



From 250 c.c. of solution 10,000 parts of soil absorbud 20 parts. 

 500 " " " " " " " " 25 " 



" 1,000 " " " " " " " " 29 " 



The quantity of a substance absorbed by the soil de- 

 pends somewhat on the state of combination it is in, i, e., 

 on tlie substances with which it is associated. Peters 

 found, for example, that 10,000 parts of soil absorbed from 

 solutions of a number of potash-salts, each containing 

 '1 ,3 of an equivalent of that base expressed in grams, to 

 the liter, the following quantities of potash : — 

 From phosphate, 49 parts. 



« hydrate, 40 « 



" carbonate, 32 " 



" bicarbonate, 28 " 



« nitrate, 25 « 



« sulphate, 21 « 



" chloride* and carbonate, 21 " 

 « chloride, 20 « 



• ChloriUe of Potassium, KG!. 



