ANTAGONISM 161 



start and remain so (i. e., if their relative proportions are 

 not too much, changed by unequal speed of diffusion, 

 precipitation, chemical union, etc.) after they enter the 

 cell. For they must affect the life processes mentioned 

 above in quite the same way in the interior of the cell 

 as at the surface, and these life processes will go on in the 

 normal way so long as the antagonistic substances within 

 the cell remain properly balanced. 



The result will be the preservation of normal per- 

 meability as well as of all other properties essential 

 to life. 



It has been shown^^ that the normal permeability 

 may be regarded as a sensitive and accurate indicator 

 of health and vitality. All factors which disturb it bring 

 about temporary or permanent injury and eventually 

 produce death if the action be sufficiently prolonged. It 

 is therefore evident that the life processes which pre- 

 serve normal permeability are of peculiar importance 

 and that the manner in which they are influenced by 

 antagonistic substances is of especial interest. 



We may now turn our attention to another aspect 

 of the subject. Explanations have been suggested by 

 Loeb and others to account for the antagonistic action 

 of various substances on living protoplasm, but none of 

 them have thus far developed to the point where they 

 enable us to predict what substances (including both elec- 

 trolytes and non-electrolytes) will antagonize each other 

 and what degree of antagonism may be expected. 



This kind of prediction is apparently made possible 

 by a hypothesis formulated by the writer, as the result 



■ Whatever effects are found at the outer surface of the cell may doubt- 

 less be found also at many of the internal surfaces, such as the surfaces of 

 vacuoles, plastids, microsomes, etc. See Chapter VII. 

 11 



