98 
Journal of Agricultural Research 
Vol. a6. No. 3 
The presence of KC 1 was evident in the decreased number of OH ions 
produced by the addition of Ca(OH) 2 . This was true for both suspen¬ 
sions and extracts, and similar to results obtained in preceding experi¬ 
ments in which KC1 was used. The figures for calcium adsorption are 
very similar to those obtained in Experiment 6. In the short time con¬ 
tact of this experiment the total effect of KC1 was not influenced by the 
presence of CaC 0 3 . 
Fig. 5.—Curves showing the influence of KC 1 on the adsorption of Ca from Ca(OH)2+CaCOi. 
EXPERIMENT 9 .—SOILS + DILUTE HYDROCHLORIC ACID 
In this experiment the plan was to add 0.04N HC 1 to three soils in 
portions stoichometrically equivalent to the calcium used in several of 
the preceding experiments. The calculated amount of 0.04N HC 1 was 
added to the soil with enough water to make the ratio of soil and liquid 
1:10. The time of shaking and the duration of the digestion was the 
same as in the preceding experiments. Oswego silt loam, Bates very 
fine sandy loam, and Bates loam were used. The data obtained are 
presented in Table IX. 
Table IX. — Ph on suspensions and extracts of soil-{-HCl, also titrations and calcium 
content of the extracts 
HC 1 added. 
Oswego silt loam. 
Bates very fine sandy loam. 
Bates loam. 
3 £ 
Ca equiva¬ 
lent. 
Suspension. 
Extract. 
6 Z 
Calcium in 
extract. 
Suspension. 
Extract. 
fcM 
°z 
Calcium in 
extract. 
Suspension. 
Extract. 
°z 
Calcium in 
extract. 
Cc. 
Mgm- 
Pr- 
P H‘ 
Cc. 
Mgm. 
P H- 
PIT¬ 
Cc. 
Mgm. 
Pr- 
Pr- 
Cc. 
Mgm 
3.12 
2. 5 
4. 78 
5 - 19 
0.4 
1.9 
4 - 14 
S' 93 
0 .5 
6. 00 
5 . 36 
O. 2 
2. 2 
6.25 
5 * 0 
4. 21 
4. 82 
•4 
3 - 1 
3 - 70 
4. 12 
•9 
3-2 
5 - 33 
5 * 33 
. 2 
4.2 
12.5 
10. 0 
3. 16 
3-76 
1. 0 
6.4 
3-23 
3-09 
4-5 
4.0 
4 - 38 
4- 65 
•3 
6.8 
25.0 
20. 0 
2. 72 
2. 76 
5-6 
10. 0 
2.44 
2.38 
13.6 
4.2 
3.22 
3 - 57 
1. 7 
13. 2 
50.0 
40. 0 
2. l8 
2. 14 
23.2 
12.4 
2. 04 
1. 91 
32.9 
4.6 
2. 42 
2. 48 
12.4 
20. 2 
