388 CAUSE OF INFLUENCE OF IONS, I 



needs further investigation. The present paper deals only with 

 concentrations inside the anomalous range. 



It was shown in the preceding papers that all the anomalies can be 

 adequately described if we assume that the water in diffusing through 

 the pores or interstices of the membrane is either positively or 

 negatively charged and that the ions of the solution accelerate or 

 retard the diffusion of the electrified water by their electrical charges. 

 When we use collodion membranes which have been bathed for a 

 short time in a 1 per cent solution of a protein (gelatin, casein, egg 

 albumin, edestin, etc.) the effects of the two oppositely charged ions 

 can be expressed in the following terms. 



1. When we separate a neutral, alkaline, or faintly acid solution 

 of an electrolyte with a monovalent or bivalent cation by a collodipn 

 membrane (treated with protein) from pure water, the latter diffuses 

 into the solution as if its particles were positively charged and as if 

 they were attracted by the anion and repelled by the cation of the 

 solution with a force increasing with the valency of the ion and with 

 a second constitutional quantity of the ion which we designated 

 arbitrarily as the radius of the ion, but which needs another definition 

 so as to include the strong effects of such monovalent ions as; e.g., 

 the aluminate or oleate anion. 



2. When we separate solutions of electrolytes with a concentration 

 of hydrogen ions of about 10~^ n or above, or with trivalent or 

 tetravalent cations in sufficient concentration by a collodion mem- 

 brane from pure water, water diffuses into the solution as if its particles 

 were negatively charged and attracted by the cation and repelled by 

 the anion of the electrolyte with a force increasing with the valency of 

 the ion and with a second constitutional quantity of the ions still 

 to be defined. 



When we use collodion membranes not treated with protein one 

 rule suffices to express all the phenomena; namely, water diffuses 

 through the collodion membrane into the solution as if its particles 

 were positively charged and as if it were attracted by the anion and 

 repelled by the cation of the solution with a force increasing with 

 the valency and a second quantity of the ion which is still to be 

 defined. 



