INFLUENCE OF THE ALKALI SALTS UPON THE GROWTH OF RICE PLANTS. 265 
decreased and especially calcium has a strong antagonistic action which 
served as protection of root growth. 
Toxic and antagonistic effects of salts as related to ammonification 
by Bacillus subtilis were also studied by Lipman 1 ' and the following 
conclusions were reported: "1. Each of the four chlorides (CaQ 2 , MgCl 2 , 
KCl, NaCl) is toxic lor Bacillus subtilis, in the order given, the first 
being the most toxic and the fourth the least. This is quite different 
from the results with higher plants, where magnesium is the most toxic 
and calcium the least. 2. A marked antagonism exists between calcium 
and potassium, magnesium and sodium, potassium and sodium. 3. No 
antagonism exsists between magnesium and calcium, but the toxic effect 
of each is increased by combination with the other. This is just the 
opposite of what has hitherto been found for plants". 
As yet no investigation has been made regarding the antagonistic 
effects of salts upon the growth of rice plants, we have selected the chlorides 
of sodium, potassium, magnesium and calcium, and the sulphates of sodium, 
potassium and magnesium, the nitrates of sodium and potassium, as the 
salts to be tested and examined the respective antagonisms between these 
two salts in different combinations by one of the following methods. 
Method A. Eight beakers of about 5.5 cm. diameter and 7 cm. deep, 
each containing 30 cc. of culture fluids, served for the experiment. Seven 
beakers received 1/10 N. A 2) solution 30 cc, 1/10 N. A solution 25 cc. + 
1/10 N. B 2) solution 5 cc, 1/10 N. A solution 20 cc. + 1/10 N. B solu- 
tion 10 cc, 1/10 N. A solution 15 cc. + 1/10 N. B solution 15 cc, 1/10 
N. A solution 10 cc. + 1/10 N. B solution 20 cc, 1/10 N. A solution 5 
cc. + 1/10 N. B solution 25 cc. and 1/10 N. B solution 30 cc. respectively, 
while 1 beaker containing distilled water served as control. The young 
rice seedlings which were grown in distilled water from seeds of almost 
uniform size and specific gravity (1.1 85-1. 200), were transplanted into the 
beakers, each receiving five healthy individuals of uniform size (about 10- 
1) . Lip man, — Bot. Gaz., 48, PP- 105-124 (1909). 
2) . A and B denote the salts to be tested in the experiment. As already proved in the 
previous chapter, a pure solution of the salts under test is very injurious upon the growth of 
rice seedlings in the concentration of 1/10 normal. 
