INFLUENCE OF THE ALKALI SALTS LTON THE GROWTH OF RICE PLANTS. 263 
II. On the Antagonism between two Salts 
relating to their toxic Effect upon the 
Growth of Rice Seedlings. 
The results of the experiments with single salt solutions have been 
described in the preceding chapter, but it can not be correlated with our 
knowledge of alkali soils, since as Kearney and Cameron 0 pointed 
out, in nature we have always to do with a mixture of salts and never 
with single solutions. They found in connection with Loeb's striking 
results with marine animals that by adding sodium salts to the solution 
of magnesium salts the critical concentrations of the latter could be raised 
considerably and in the case of Litpiims albas and Mcdicago saliva, the 
neutralizing effect became enormous when salts of calcium were added to 
the solutions of sulphates and chlorides of magnesium and sodium. 
The physiology of the decreasing toxicity of a salt due to the presence 
of a second salt in the solution, was specially discussed by Osterhout 2) 
from the view point of Loeb's conception of a "physiologically balanced 
salts solution". As the result of investigations, it has been shown that 
marine plants as well as marine animals are very sensitive to pure salt 
solutions, but thrive well in solutions containing a mixture of salts, even 
though each component is present in an amount that is toxic in pure 
solution. A mixture of the more important salts present in sea water, 
each at about the concentration at which it occurs in the sea, was found 
to be the best medium for the growth of marine algea. Moreover, the 
same phenomenon has been observed in the case of land plants. 
Kearney and Harter 8 ' also investigated the neutralizing effect of 
calcium sulphate upon the toxicity of magnecium and sodium salts with 
1 ) . Kearney and Cameron , — 1. c. 
2) . Osterhaut, — Jour. Biol. Chem., 1, pp. 363-369 (1906); Bot. Gaz., 42, PP- 127-134 
(1906); Univ. Cal. Pubs. Bot, 2, p. 317 (1907); Jahrb. f. Wissensch. Bot., 46, P- 121 (1908); 
Bot. Gaz., 45, P- 117 (1908); Univ. Cal. Pubs. Bot., 3, PP. 331-337 (1908); Bot. Gaz., 48, PP- 
98-104 (1909). 
3) . Kearney, and Harter, — !, c. 
