268 ELECTRIFICATION OF WATER 



of water are attracted more powerfully by Na2S04, less powerfully by 

 NaCl, and still less powerfully by CaCl2. Hence when we make 

 m/128 solutions of these three salts acid through the addition of HNO3, 

 and if it is true that water diffuses through the membranes not treated 

 with gelatin in the form of positively charged particles in the presence 

 of strong acid, it should diffuse more rapidly into Na2S04, less rapidly 

 into NaCl, and least rapidly into CaCl2. m/128 solutions of these 

 three salts were brought to a pH of 2.9 through the addition of HNO3, 

 and the experiment turned out as the theory demands. When the 

 same experiment was made with collodion membranes treated with 

 gelatin, the order of attraction of the three salts of pH 2.9 for water 

 was reversed, water diffusing very rapidly into the acid solution of 

 m/128 CaCla, less rapidly into the acid solution of m/128 NaCl, and 

 still less rapidly into the acid solution of m/128 Na2S04, since in this 

 case the particles of water diffusing through the membrane were 

 negatively charged. When the solutions of the three salts were 

 neutral or alkahne, no difference in the osmotic behavior of the two 

 types of membranes was noticed. 



ni. 



In a previous paper^ the writer had suggested that it was necessary 

 to discriminate between the influence of cations upon the sign of 

 electrification of water and upon the rate with which electrified 

 water diffuses into the solution. This suggestion receives support 

 from this paper, and it is impossible to understand the phenomenon 

 of negative osmosis without this discrimination. Thus it is obvious 

 that both H ions as well as trivalent cations cause the particles of 

 water which normally have a positive charge, to assume a negative 

 charge and it is not yet possible to state whether the H ions or the 

 trivalent cations are more efficient in this direction. It follows, 

 however, from the observations pubhshed in this paper that, as far 

 as the rate of diffusion of the charged particles of water into the 

 solution is concerned, the influence of the trivalent cations is much 

 more powerful than that of the hydrogen ions. We express this 

 influence in tenns of electrostatic attraction and repulsion between 

 the ions and the charged particles of water, not in order to offer 

 thereby an explanation of this influence but merely to simplify the 



