Oct. 16, 1916 
Acidity and Adsorption in Soils 
131 
Table) V. —Titration of soil suspensions with calcium hydroxid f07 lime requirement 
Quantity of calcium 
hydroxid added 
H-ion concentration. 
Soil No. 
Quan¬ 
tity of 
soil. 
Water. 
(calculated to cal¬ 
cium carbonate) . 
Original. 
After titration. 
Time 
of titra¬ 
tion. 
Entire 
quantity. 
Per gram 
of soil. 
Volt¬ 
meter 
read¬ 
ing. 
Gram 
molecules 
per liter. 
Volt¬ 
meter 
reading. 
Gram 
molecules 
per liter. 
15...'... 
Gm. 
5 
C. c. 
50 
Gm. 
0. 0085 
Gm. 
O. 00x7 
0.590 
0.4X10- 4 
775 
0. 2 X io~ 7 
Hours. 
3 
15 . 
5 
5 ° 
. 0128 
. 0026 
• 59 ° 
.4X10- 4 
• 796 
. iXxo" 7 
44 
16. 
2 
50 
.0054 
. 0027 
.654 
• 3X10 5 
• Z 61 
. 4Xio~ 7 
26 
*7 . 
2 
5 ° 
. 0061 
. 0030 
. 611 
. 2XlO -4 
• 759 
.5X10- 7 
26 
17. 
2 
5 ° 
. 0070 
• 0035 
•599 
.3X1O -4 
• 757 
.5X10- 7 
5 
19. 
2 
5 ° 
. 0081 
. 0040 
.638 
. 6XlO 5 
• 77° 
.3X10 7 
25 
20. 
2 
5 ° 
•0053 
. 0026 
.618 
. iXxo" 4 
•754 
. 6X10 7 
3 
20. 
2 
50 
. 0047 
. 0023 
. 623 
. IXIO- 4 
• 757 
.5X10- 7 
5 
18. 
2 
50 
. 00068 
. OOO34 
• 707 
.4XIO- 6 
• 758 
.5X10- 7 
20 
Table VI .—Results of beaker and pot studies 
Soil in 
beaker or 
pot. 
Total 
quantity 
of calcium 
carbonate 
added. 
Calcium 
Treated 
soil 
tested. 
Reaction of treated 
soii. 
Soil 
No. 
carbonate 
per gram 
of soil. 
Water. 
Read¬ 
ings on 
volt¬ 
meter. 
H ion (gram 
molecules 
per liter). 
Remarks. 
15. . 
Gm. 
200 
Gm. 
O. 200 
Gm. 
0. OOI 
Gm. 
5 
C. c. 
50 
0. 664 
0. 2X10" 5 
Incubated 7 days at 
I 5 -- 
200 
. 400 
. 002 
5 
50 
• 799 
. 9X10 -8 
30° C. 
Do. 
15 . • 
11, 200 
IO. 0 
. OOO9 
5 
50 
. 630 
. 8X10 -5 
In jar 2 months. 
15 - * 
II, 200 
15-0 
. OOI3 
5 
50 
•733 
. iXicr 6 
Do. 
16. . 
5 ° 
• 135 
. OO27 
5 
50 
•752 
. 6X10 7 
Incubated 7 days at 
17. . 
25 
' . 090 
. OO36 
5 
5 ° 
. 728 
.2X1O- 0 
3 °° £• 
Do. 
17 . . 
5 ° 
. 250 
.0050 
5 
5 ° 
• 777 
. 2X1 o —7 
Do. 
18. . 
5 ° 
. 017 
. OOO34 
5 
5 ° 
• 740 
1. 0X10 -7 
Do. 
19. . 
25 
. IOO 
. OO40 
5 
5 ° 
•755 
. 5X10- 7 
Do. 
20. . 
25 
• 06$ 
. 0026 
5 
5 ° 
. 780 
. 2X10 7 
Do. 
* Such a method is logically adapted to obtain the information neces¬ 
sary for the proper adjustment of the soil reaction by the addition of 
lime. There are, however, certain difficulties met with in its application 
to soils. One of the chief obstacles is due to the relative insolubility of 
the acid-forming constituents of soils, which prevents a rapid attain¬ 
ment of equilibrium. This drawback can probably be overcome by the 
use of a shaking machine. Another but presumably minor source of 
error lies in the loss of C0 2 from the soil suspension, as previously 
mentioned. 
In order to determine whether the titrations with calcium hydroxid 
might serve as a guide for the application of lime necessary to produce a 
neutral or slightly alkaline reaction several beaker and pot studies were 
undertaken. A reference to Tables V and VI shows that in these soils 
approximate neutrality resulted from the admixture of calcium carbon- 
