2(^2 K. MIYAK.E. 
The results show that in all the concentrations tried, the suitable 
ratio of the cations, calcium and magnesium or calcium and sodium had 
a favorable effect upon the growth of the plants. The plants did much 
better where calcium and magnesium or calcium and sodium were present 
in the ratio 5 : 25. 0 The more concentrated the solution the greater 
was the difference in effect between the ratio 5 : 25 and the other ratios. 
In higher concentrations than dicinormal, however, the plants did not 
grow so well as in distilled water even in the most favorable ratio. 
V. Influence of a third Salt upon the Growth 
of Rice Seedlings in a Mixture of two Salts. 
Some years ago L o e b !) and Ost wa 1 d 3) found from the study of 
marine and freshwater animals that as the toxicity of a pure solution is 
diminished by the addition of a second salt, so is the toxicity of certain 
mixtures diminished by the addition of a third or fourth salt, and by 
addition of various salts a mixture known as balanced solution (i. e., one 
which is no more injurious than distilled water) can finally be obtained. 
In view of this fact, Osterhouf 0 made a number of experiments with 
the salts which are contained in sea water with marine, freshwater as 
well as land plants and proved that facts similar to those mentioned 
above are also observed even in plants. According to him, the order of 
1) Some years ago Loew advanced the theory that plants made their maximum growth- 
other conditions, of course, being favorable — when the available lime and magnesia are present 
in a certain ratio to each other, the optimum ratio for rice plants being to CaQ = I. But, 
MgO 
this ratio of lime to magnesia seems to apply only in a medium in which a sufficient amount 
of other nutritive salts is present. 
2) Loeb, — Pflüger's Archiv, 107 P. 252 (1905). 
3) O s t w a 1 d,-Ibid., 106 P. 568.(1905)- 
4) Osterhout,— Bot. Gaz., 42, P- 127 (1906); 44, P- 259 (1907). 
