COPPER AND ZINC AS ANTAGONISTIC TO " ALKALI " SALTS 1 55 
any spots on the pot from which the paraffine has disappeared in one 
way or another always become centers of absorption for Na2S04, which 
then readily disintegrates the pottery. In spite of these disturbing 
elements in the experiment, there can be no question that CUSO4 has 
Table I 
Antagonism Between CuSOa and NatSO^ For Barley — Adobe Soil, First Crop 
i\ 0. 
io Na2S04 
Added 
CUSO4 in 
Parts per 
Million 
Wt, 01 Straw 
Wt. of 
Grain 
Wt. Dry Mat- 
tcr Above 
Surface 
Wt. of 
Roots 
Wt. of Total 
Dry Matter 
g- 
g- 
g- 
g- 
g. 
I 
.5% 
100 
6.98 
8.02 
15.00 
1.80 
16.80 
2 
.5% 
100 
5-73 
2,27 
8.00 
1.30 
9-30 
3 
.5% 
200 
8.50 
4-50 
13.00 
2.70 
15.70 
4 
.5% 
200 
6.90 
4.10 
11.00 
2.00 
13.00 
5 
.5% 
300 
7-25 
5-95 
13.20 
1.70 
14.90 
6 
.5% 
300 
7.70 
4-30 
12.00 
1. 00 
13.00 
7 
.5% 
400 
8.85 
5-15 
14.00 
1.50 
15-50 
8 
.5% 
400 
9.20 
3.60 
12.80 
2.80 
15.60 
9 
.5% 
500 
11.60 
5-50 
17.10 
2.30 
19.40 
10 
.5% 
500 
8.30 
5.20 
13-50 
2.00 
15-50 
II 
.5% 
600 
8.23 
5-27 
13-50 
2.00 
15-50 
12 
.5% 
600 
9-15 
3-35 
12.50 
2.50 
15.00 
13 
.5% 
700 
9-25 
5-15 
14.40 
2.40 
16.80 
14 
.5% 
700 
6.40 
3.60 
10.00 
1.40 
11.40 
15 
.5% 
800 
9.20 
5-30 
14.50 
1.90 
16.40 
16 
.5% 
800 
7-55 
3-95 
11.50 
1.20 
12.70 
17 
.5% 
7-13 
2.17 
9-30 
.85 
10.15 
18 
.5% 
7-33 
1.07 
8.40 
1.50 
9.90 
19 
IC.70 
10.70 
• 2.50 
13.20 
20 
14.00 
4-30 
18.30 
2.00 
20.30 
21 
12.05 
1-75 
14.80 
1.40 
16.20 
exercised a definitely antagonistic effect to the toxicity of Na2S04. 
Concentrations no greater than 500 parts per million CUSO4 were 
sufficient in all cases to give the maximum antagonism to .5 percent 
of Na2S04, and in the second and third crops, which are probably more 
reliable criteria than the first crop, 100 and 200 parts per million were 
fully as efficacious, if not more so than the larger amounts. These 
considerations would seem to indicate that amounts of CUSO4 equiva- 
lent to from one tenth to one fiftieth of the amount of Na2S04 present 
are sufficient to antagonize the latter salt when it is present in soil at 
concentrations of about .5 percent. 
As regards grain yields, the antagonism of CUSO4 to Na2S04 is 
much more marked than in the case of straw yields. This is particu- 
larly so for the first and second crop of the series. In the third crop, 
