312 



NEWTON BALDWIN GREEN 



may be divided into three classes as regards their effect upon 

 each other in relation to the gelatine. Members of any one 

 group give additive effect when mixed together. But when two 

 individuals from different groups are mixed the effect is antago- 

 nistic. This antagonism is between unadsorbed ions bearing 

 opposite electrical charges, and is made possible by the tendency 

 on the part of the gelatine to adsorb more of one kind of ion than 

 of the other. 



Fig. 6 



He showed that NaCl and CaCl2 belong to different groups 

 and that mixed in proper proportion and concentration they 

 caused precipitation without the addition of any alcohol what- 

 soever. From this he postulated his theory that antagonistic 

 salts produce a precipitate or state of aggregation of an isoelectric 

 nature in the protoplasm, and that protoplasmic permeability is 

 directly dependent upon the amount of this precipitate, being 

 inversely proportional to it. 



