SALTS 443 



There are other serious objections to the valency grouping of 

 ions from the physiological point of view. Monovalent cations 

 antagonize each other, and so do bivalent ones. Rubinstein 

 found that the toxicity of sodium manifests itself in a number of 

 ways and that calcium will counteract it in one way only, while 

 potassium counteracts it in still another way. Here two mono- 

 valent elements (sodium and potassium) and a monovalent and 

 a bivalent element (sodium and calcium) antagonize each other. 

 Stover found that mice eating food containing a mixture of 

 calcium carbonate and barium carbonate (a poison) are unharmed. 

 Here bivalent metals (calcium and barium) antagonize each 

 other. The results of Trelease were similar, the antagonism 

 being between two bivalent ions. Gellhorn found that calcium 

 decreases the fatigue of muscles, while barium (and strontium) 

 increases it; combined, the elements have no effect. Thus does 

 calcium antagonize barium, although each is bivalent. The 

 action is specific in that the calcium cannot be wholly replaced 

 by magnesium. There is also a slight antagonism between 

 the two monovalent ions sodium and potassium. 



We are deaUng here with two facts both of which oppose the 

 valency grouping of ions in physiological processes; first, while 

 monovalent ions (sodium) are opposed by bivalent ones (calcium), 

 it is equally true that monovalents (sodium) oppose monovalents 

 (potassium) and that bivalents (calcium) oppose bivalents 

 (barium). Furthermore, not every member of a group will do 

 as an antagonist; thus, magnesium will not replace calcium. 

 This last fact is further supported by the work of Pantin, who 

 found that calcium, in certain cases, can be replaced by strontium 

 but not by magnesium or barium. 



The nature of salt antagonism is unknown. It was first 

 thought that the ions opposed each other in solution, that is to 

 say, that the antagonism was outside the cell. One might 

 imagine two opposing armies meeting on a field of battle outside 

 the city walls, each preventing the other from entering and doing 

 damage. But this hypothesis has little to support it. More 

 reasonable is the possibility that ions exhibiting antagonistic 

 action exercise an opposite effect on protoplasm. If sodium 

 produces one effect upon protoplasm and calcium an opposite 

 effect, then these two elements in proper proportion should 

 leave the protoplasm unchanged. This they apparently do in 



