654 
Journal of Agricultural Research voi. xxvii, No. 9 
and magnesium. The soil was of such texture that it was supersaturated 
with 30 per cent of water. This made it possible to extract with a suction 
filter enough of the solution for analysis when 100 parts of soil was 
digested with 40 parts of water. The experiment included digestion of 
equal quantities of the same sample of soil with quantities of water 
ranging from 40 parts per 100 up to 2,500 parts per 100. After the soil 
had been digested with water for 24 hours, with repeated shaking, a 
portion of the solution was withdrawn from analysis. 10 The total solids 
were determined by evaporation and the organic matter by igniting the 
dried residue. The other constituents identified were the carbonate, 
bicarbonate, chlorin, and sulphate. 
Table XVIII .—Effect of diluting the soil solution on the balance of its constituents, the 
total solids being expressed as percentages of the dry weight of the soil and the constituents 
as percentages of the total solids a 
Dilution ratio of water to soil. 
Total 
solids. 
Constituents as percentage of total solids. 
Organic 
matter. 
CO.+ 552 . 
2 
Cl. 
so*. 
Total 
acids. 
0. 76 
7-3 
9 - 7 
19-3 
35-7 
. 64. 7 
0.5:1. 
• 77 
7.8 
9 - 7 
17. 1 
34 . 6 
61. 4 
.82 
9 - 7 
11. 6 
14. 1 
32. 7 
58.4 
2.5:1. 
.87 
io- 5 
12. 9 
14. 0 
29. 7 
56.6 
5 :i--. 
•94 
9.9 
14.4 
14. 2 
27- 5 
58. 1 
10:1. 
•99 
12. 1 
16. 3 
14. 1 
25. 8 
56. 2 
25:1. 
1. 12 
j 
15 - 
20. 1 
12. 5 
20. 8 
53-4 
a Reported by J. F. Breazeale. 
The analysis of these solutions showed that the total quantity of dis¬ 
solved material obtained from a unit quantity of soil increased from 0.76 
per cent when 40 per cent of water was used to 1.12 per cent when the 
2,500 per cent of water was used. The important constituents of the 
solution are reported in four groups—organic matter, carbonates, chlo¬ 
rin, and sulphate. When these constituents are reported as percentages 
of the total solids it is observed that two of them, the organic matter and 
the carbonates, show increasing percentages with increasing dilutions, 
while the other two show decreasing percentages. If these constituents 
were reported as percentages of the original soil it would be seen that 
while the percentages of chlorin and sulphate are practically the same 
for all dilutions, the percentage of organic matter increases from 0.055 
per cent with 40 per cent of water to 0.170 per cent with 2,500 per cent 
of water. The increase in the percentage of carbonate and bicarbonate 
to the dry soil is even more marked, being from 0.074 with 40 per cent 
to 0.225 at 2,500 per cent. 
It is obvious from the results of this experiment why investigators 
hesitate to make assumptions concerning the concentration or character 
of the soil solution as it is available to crop plants when their only infor¬ 
mation is based upon the analysis of extracts made with 5, 10, or even 
20 parts of water to 1 part of soil. With such a soil as that used in the 
10 This experiment was conducted and the analysis made by J. F. Breazeale. 
