jan. 17,1916 Effect of Sulphur and Calcium Sulphate on Plants 777 
representative plants were removed from each jar. The roots of the 
plants grown in the sulphate-treated soil were longer and more branched 
than those of the plants grown in the untreated soil. There was an 
apparent increase in the number of nodules grown in the sulphate-treated 
series, except in the case of plants grown on soil to which 0.1 per cent of 
calcium sulphate had been added. The number of nodules on the above 
plants were about the same as on the plants grown in untreated soil. It 
must be remembered that the plants grown in the soil containing 0.1 per 
cent of calciuim sulphate were smaller and therefore would naturally con¬ 
tain fewer nodules than the larger plants. Plate LVI, figure 2, illustrates 
these effects. The plants in group A were taken from the untreated soil; 
B, from the soil to which 0.01 per cent of calcium sulphate had been 
added; C, from soil to which 0.02 per cent had been added; D, from soil, 
to which 0.05 per cent had been added; and E, from soil to which o.r 
per cent of calcium sulphate had been added. Note the marked increase 
in root development in B, C, D, and even E, where the plants are the 
same size as those in group A; also note that group E, to which 0.1 per 
cent of calcium sulphate was added, and D, to which 0.05 per cent was 
added, show no greater growth than A, the untreated, while groups B 
and C show an increase in top as well as root. The illustration shows 
very distinctly the increase in length of root and also the decrease in the 
growth of the plant under high concentrations of calcium sulphate. . It 
is apparent that the addition of 0.02 and 0.05 per cent of calcium sulphate 
gave the most beneficial results. 
Table VIII .—Effect of calcium sulphate on the growth of red clover in soil 
Treatment. 
Number of 
nodules. 
Average of 
group. 
Eength of 
root. 
Average of 
group. 
Untreated. 
Cm. 
9 
12 
Cm. , 
Cm. 
6. s 
8-5 
6.8 
7 -o 
8. 0 
10. 0 
10. 5 
0 0 
Cm. 
Do.... ... 
Do... 
8 
IO 
7.2 
Do. 
10 
29 
Given 0.01 per cent of calcium sulphate. 
Do. 
Do. 
00 
11 
31 
> 9.6 
Do. 
5 1 
34 
17 
Given 0.02 per cent of calcium sulphate. 
Do. 
8. 0 
Q 6 
Do. 
48 
72 
33 
y* u 
12. 0 
8.5 
9.0 
6. 5 
IT *2 
9 - 5 
Do. 
Given 0.05 per cent of calcium sulphate. 
Do. 
45 
3<5 
18 
10 
Do. 
29 
9. 2 
Do. 
0 
: 1Im 5 
7 . O 
7 - 5 
8 - 5 
7 - 5 . 
Given 0.1 per cent of calcium sulphate...... 
13 
11 
Do. 
Do. 
12 
14 - 
7. 6 
Do. 
11 
17210°—16 - 5 
