I62 
C. B. LIPMAN AND W. F. GERICKE 
with no salt treatment were inadvertently omitted from the series. 
This omission in the experiment is regrettable, but owing to the definite- 
ness of the toxic effects of Na2S04 obtained and to the equally definite 
evidences of antagonism between zinc and sodium, it does not militate 
seriously against the usefulness and significance of the results. 
Table VII 
Antagonism Between ZnSoi and Na^SOi For Barley — Adobe Soil, One Crop 
ic Na2S04 
ZnS04 in 
Wt. of 
Wt. Dry Mat- 
No. 
Parts per 
Million 
Wt. of Straw 
ter Above 
Wt. of Roots 
Added 
Grain 
Surface 
I 
.6% 
g- 
5-30 
g- 
2.10 
g- 
7.40 
Did not harvest roots. 
2 
.6% 
5.60 
2.00 
7.60 
Could not get them 
3 
.6% 
100 
5.20 
4.00 
9.20 
out of bottles. 
4 
.6% 
100 
5.80 
2.80 
8.60 
5 
.6% 
300 
7.10 
4.90 
12.00 
6 
.6% 
300 
540 
2.20 
7.60 
7 
.6% 
500 
6.00 
4.00 
10.40 
8 
.6% 
500 
7.30 
3-30 
10.60 
9 
.6% 
700 
11.30 
4-50 
15-80 
lO 
.6% 
700 
7.70 
3.80 
11.50 
II 
.6% 
1,000 
12.60 
2.80 
15.40 
12 
•6% 
1,000 
12.50 
4-30 
16.80 
The straw yields are clearly influenced for the better by the appli- 
cations of ZnS04 to the Na2S04-treated soil. Particularly is this true 
of cultures receiving the larger applications of ZnS04. There can be 
no doubt of the definite antagonism indicated in these data. In the 
case of the grain yields likewise, the evidences of antagonism are very 
clear, but the smaller concentrations of ZnS04 appear to have been as 
effective in antagonism as regards grain production as the larger con- 
centrations of that salt. It was found impossible to remove the soil 
from the bottles at the end of the experiment in such a fashion as to 
permit of the determination of root yields. Hence the latter are not 
given in the table. It is to be noted in connection with Series IV that 
the agreement between duplicate cultures is much better in bottles as 
containers than in pots. Particularly when alkali salts are involved, 
the use of bottles or similar glass containers would seem to deserve 
preference over even paraffined pots. Whether or not the ordinary 
glazed crocks now employed by us will combine the advantages of the 
glass with the advantages of earthenware pots will, we hop bee, soon 
determined. 
