114 CHEMICAL EQUILIBRIUM AND ANTAGONISM 



be assigned to the formation of new and less toxic com- 

 pounds; but magnesium sulphate with sodium sulphate, 

 sodium sulphate with magnesium chloride, sodium chloride 

 with magnesium sulphate, and similar combinations which 

 exist as stable compounds in contact with each other 

 were also corrective of each other. It was further found 

 that when the different salts were present in certain pro- 

 portion to each other the effect was different than where 

 other apparently less toxic proportions were used. When 

 398 parts per million of sodium carbonate and 710 parts 

 per million of sodium sulphate were in the same solution, 

 some of the plants lived; but when the sodium sulphate 

 was reduced to half this quantity, all the plants died. 



A number of other experimenters have noticed the 

 antagonistic action between calcium and magnesium salts 

 when in solutions with sodium salts. Miyake (16), work- 

 ing with rice plants, found that there was a slight antago- 

 nism between the monovalent anion, chloride, and the 

 divalent anion, sulphate, but it was small compared with 

 that between the cations. He found potassium antago- 

 nistic to sodium when the two salts were together in the 

 form of sulphates, chlorides, or nitrates. 



The quantity of salts which caused injury to the plants 

 growing in the solutions of these experiments is much be- 

 low the quantities ordinarily found to cause injury in field 

 or soil experiments, especially where the unmixed solutions 

 were used. It has been suggested that the reason for the 

 lower toxicity in the soils is because the soil contains cal- 

 cium and other salts which ameliorate the effect of the 

 injurious salts. Whether this explanation is sufficient to 

 account for all of the difference is questionable, however. 

 That lime is a good corrective for magnesium, as reported 

 above, is shown by the fact that certain Canadian soils (19) 



