Oct. 20, X923 
Soil Reaction in Relation to Calcium Adsorption 
97 
Table VII.— Ph on suspensions and extracts of soil-t-CaC0 8 -\-Ca(OH 2 ), also titrations 
and calcium content of extract and calcium adsorbed by soil 
Ca added in 
Ca(OH) 2 . 
Ca added 
in CaCOs. 
Suspen¬ 
sion. 
Extract. 
0.05N HC 1 . 
Calcium 
in 
extract. 
Calcium 
not 
adsorbed. 
Calcium 
adsorbed. 
Mgm . 
Mgm. 
Ph- 
Ph • 
Cc. 
Mgm • 
Mgm . 
Mgm. 
2-5 . 
2-5 
7 - 1 
7-7 
— O. 2 
2.4 
O. O 
2-5 
5 . 
5 
7.6 
8.0 
-. 2 
2.4 
. O 
5 - 0 
8. 
8 
7 - 73 
8.4 
. 2 
2.4 
. O 
8. 0 
12. 
12 
7.96 
8. 54 
. 2 
2.4 
. O 
12. 0 
16. 
16 
8. 27 
8- 57 
•4 
2.4 
. O 
16. 0 
20. 
20 
8.81 
8. 67 
1. 2 
2. 4 
. O 
20. 0 
28. 
28 
9.69 
9 - 15 
1.4 
3 -o 
.6 
27.4 
36. 
36 
10. 46 
10.43 
i -5 
4.6 
2. 2 
33-8 
48. 
48 
n.38 
11. 14 
4. 1 
8.4 
6. 0 
42. O 
60. 
60 
n -55 
53 
10.4 
14-3 
II. 9 
48. I 
80. 
80 
11.88 
11.85 
20.3 
25.6 
23. 2 
56.8 
The influence of the smaller quantities of CaC0 3 added was apparent 
in the greater hydroxyl-ion concentration produced with the smaller 
additions of Ca(OH) 2 solutions. Where the larger portions of Ca(OH) 2 
were added, the influence of the equivalent amounts of CaC 0 3 on the 
P H values was nil. Here the excess of the hydroxyl-ions was so large 
as to mask completely the influence of the HC 0 3 and C 0 3 ions. The 
titer figures show that a larger amount of calcium was present as Ca(OH) 2 
or CaH 2 (C 0 3 ) 2 than in Experiment 5, but the amounts of unadsorbed 
calcium in the extracts were the same. The figures for the adsorption 
of calcium were based on the amounts added in Ca(OH) 2 . According 
to this method of calculation as much calcium was adsorbed from 
Ca(OH) 2 when CaC 0 3 was present as when it was absent. It should be 
remembered that in the 24-hours contact, equilibrium between soil and 
CaC0 3 had probably not been reached. 
EXPERIMENT 8.—SOIL “ 1 -CALCIUM HYDROXID+CALCIUM CARBONATE+POTASSIUM 
CHLORID 
This experiment was performed in all respects like No. 7, except that 
KC 1 was employed in the usual concentration. The data obtained are 
given in Table VIII. (See fig. 5.) 
Table VIII.— Ph on suspensions and extracts of soil-\-CaC0 8 -\-Ca(OH) 2 -\-KCl, also 
titrations and calcium content of extracts and calcium adsorbed by soil 
Calcium added 
in Ca(OH) 2 . 
Calcium 
added in 
CaCOs. 
Suspen¬ 
sion. 
Extract. 
0.05N 
HCL. 
Calcium 
in 
extract. 
Calcium 
not 
adsorbed. 
Calcium 
adsorbed. 
Mgm. 
Mgm. 
Pn 
Ph 
Cc. 
Mgm. 
Mgm. 
Mgm. 
2. 5 . 
2. 5 
5 - 50 
6. 40 
O. O 
17. I 
3 - I 
O. O 
5 . 
5 
7. 10 
7. 70 
. O 
19. 2 
5-2 
. O 
8. 
8 
7. 69 
7. 90 
. I 
21. 3 
7-3 
•7 
12. 
12 
8. 00 
7. 90 
. 2 
21. 6 
7.6 
4.4 
16.. 
16 
8. 10 
7.96 
•3 
21. 9 
7-9 
8. 1 
20. 
20 
8. 47 
8. 10 
• 5 
23. 8 
9.8 
10. 2 
28. 
28 
9 - 38 
8.28 
.8 
27.0 
13-0 
15 -0 
36 . 
36 
9.91 
9-35 
1. 0 
30 - 1 
16. 1 
19.9 
48 . 
48 
11. 07 
10.97 
4. 6 
35-4 
21. 4 
26.6 
60 . 
60 
11. 48 
n -37 
8.0 
42.3 
28. 3 
3 i -7 
