338 HOW CROPS 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. Potash absorbed by 
Desiqna- Quantity of potash in 250 c.c. 100 parts By 10.000 cr in Proportion 
fiom. @ " bs volt tion. of soil. ea round numbers. absorbed. 
IIo equiv, = 0.1472 gram. 0.9888 gram, 25 
Bag: Ht on 2944 O.1881 14 1 i 
yp =! 0.5888  ‘* 0.1990“ 20 iP 
ayo = 1iam7 tt 0.3124 “ 31 My 
Ms ce = 2.3555 ‘* 0.4503“ 45 1], 
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 which 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, 1000 parts of soil absorbed 20 Parts, 
ct 500 4b 17 ty “o be oe 5 
oe 1 000 ia ity +e af oF cy 3 te 29 a 
The quantity of a substance absorbed by the soil de- 
pends somewhat on the state of combination it is in, i. e., 
on the 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 
|,. of an equivalent of that base expressed in grams, to 
the liter, the following quantities of potash :— 
ion phosphate, 49 parts. 
hydrate, 40 “ 
“carbonate, 32. 
“ bicarbonate, 28 « 
“ nitrate, 25. 
«sulphate, 21 * 
“  chloride* and carbonate, 21  “ 
“ chloride, 20 
* Chloride of Potassium, KCl. 
