88 M. E. COLLETT 



sion of the acid across the egg membrane by diminishing its 

 state of hydration (Loeb ^ '^). It is also possible that at certain 

 concentrations of acid the salts may stabilize the membrane by 

 preventing coagulation, which if it occurred would destroy the 

 continuity of the membrane and increase its permeability. 



The normal electrical resistance of Laminaria (Osterhout^) is 

 greatly lowered by HCl as well as by NaCl. But if the salt is 

 added to the acid, the mixture, though still lowering the electrical 

 resistance, produces a much more gradual effect than either the 

 salt or the acid used alone. This agrees with the already known 

 antitoxic action. 



The kidney of the frog is normally impermeable to blood sugar 

 but according to Hamburger and Brinckmann the degree of 

 impermeability can be varied at will by altering either the salt 

 content or the pH of the perfusion fluid. The ratio between Ca 

 and the H ion seems to be of the utmost importance, although 

 some differences are noticeable if the amount of K orNais altered. 



Lillie-'^' -^ has studied the relations of a rather more extensive 

 series of salts and the capacity of NaCl and of HCl to diminish 

 the toxicity of bivalent cations to the cilia of Arenicola larvae 

 and of Mytilus. At the concentrations used NaCl induces 

 swelling, while HCl and the chlorides of Ba, Sr and the heavy 

 metals induce coagulation. Ca and Mg are intermediate, permit- 

 ting some swelling, but gradually producing coagulation. In mix- 

 tures of NaCl with bivalent chlorides toxicity is much lessened, 

 probably because the swelling influence of NaCl is balanced by 

 the coagulative influence of Ba, etc. Clowes^ states that in solu- 

 tions of NaCl the anion is taken up by most adsorbents more 

 readily than the cation, while in solutions of CaCl2 the cation is 

 more strongly adsorbed. This would agree with Greeley's 

 observation" that the protoplasm of Paramecium is liquefied by 

 anions and coagulated by cations. So the antagonism would re- 

 solve itself into a balance between the adsorption and activity 

 of the anion of NaCl and the cation of CaCU. Or it is possible 

 that, as Loeb^* suggests, the antagonism is between the cations 

 and is due to differences in the solubility of the Na- and Ca-pro- 

 tein salts. Lillie also found that the toxicity of NaCl and to 



