CHEMISTRY: J. WEB 
443 
lutions of NaCl acid (by dissolving the salt in M/1024 HCl) the water 
particles diffusing through the membrane are negatively charged and are 
attracted by the Na ion of the solution. This is supported by the fact 
that M/192 CaCl2 dissolved in M/1024 HCl (or HNO3) attracts water 
much more powerfully than does M/128 NaCl of the same hydrogen 
ion concentration; and the attraction of M/512 AI2CI6 of the same 
hydrogen ion concentration for water is still more powerful than that 
of CaCl2. All this is intelligible on the assumption of an electrostatic 
influence of the ions upon negatively electrified palrticles of water — no 
matter what the nature or source of electrification of water may be. 
That water is indeed electrified in the sense expressed in the two rules 
was proved directly by experiments on electrical endosmose. 
The collodion membranes are not only permeable to water but also 
to crystalloids in solutions. It could be shown by analytical experiments 
that the phenomena expressed in the two rules were not due to differ- 
ences in the rate of diffusion of the solute. The reader will find a full 
description of these experiments in a recently published paper. ^ 
3. The two rules mentioned before were based on experiments with 
solutions of about the same gas pressure, namely that of a M/64 sugar 
solution. When we compare the osmotic effect of different concentra- 
tions of sodium (or Li, K, NIT4) salts within the limit of M/8192 to 
about M/16 we find a curious phenomenon. In these experiments 
the solution of the electrolyte was put inside the collodion bag and 
the latter was dipped into a beaker with pure water. It was found 
that under these conditions the initial rise (i.e., the rise in the 
first ten or twenty minutes) of water in the collodion bag in- 
creased rapidly with the increase of the concentration of the solution, 
this initial rise reaching a maximum when the concentration of the 
electrolyte was about M/256. With a further increase of the concen- 
tration of the electrolyte the initial rate of diffusion of water from pure 
solvent into the solution dropped rapidly, reaching a minimum at about 
a concentration of M/16. We therefore notice the paradoxical fact 
that M/256 solutions of all these electrolytes attract water more power- 
fully than M/16 solutions of the same electrolytes. Thus in the case of 
a neutral solution of sodiimi oxalate the level of water rose in the manom- 
eter of the flask in twenty minutes to about 100 mm. when the con- 
centration of the solution was M/1024, to 220 mm. when the concen- 
tration was M/256, but only to 100 mm. again when the concentration 
was M/16. While I do not wish to make any assumption concerning 
the source of the electrification of water and the mechanism by which 
