442 
CHEMISTRY: J. WEB 
it was found that the influence of the nature of the electrolytes on the 
rate of diffusion of water through a collodion membrane could be ex- 
pressed in the following two rules: 
(1) Neutral solutions of salts possessing a univalent or a bivalent 
cation influence the rate of diffusion of water through a collodion mem- 
brane as if the water particles were charged positively and were attracted 
by the anion and repelled by the cation of the electrolytes; the attrac- 
tive and repulsive action increasing with the number of charges of the 
ion and diminishing inversely with a quantity which we will designate 
arbitrarily as the ' radius ' of the ion. The same rule applies to solutions 
of alkahes. 
(2) Solutions of neutral or acid salts possessing a trivalent or tetra- 
valent cation influence the rate of diffusion of water through a collodion 
membrane as if the particles of water were charged negatively and were 
attracted by the cation and repelled by the anion of the electrolyte. 
Solutions of acids and of neutral salts with monovalent or bivalent 
cation when rendered sufficiently acid obey the same rule.^ 
Thus the rate of diffusion of water into a neutral solution was con- 
siderably greater when the solution was M/128 NaCl than when it was 
M/64 cane sugar; and when different sodium or potassium salts were 
compared it was found that the rate increased with the valency of the 
anion of the salt in solution, sulfates and oxalates acting more powerfully 
than chlorides and nitrates, and citrates and ferrosulfocyanides more 
powerfully than sulfates and oxalates. The rate of diffusion of water 
was less when the solution was M/192 CaCl2 than when it was M/64 
cane sugar, and the same was true for all solutions of neutral salts with 
bivalent cation and monovalent anion. The attraction of M/128 solu- 
tions for water increased in the order Li<Na< K, showing the influence 
of the 'radius of the ion.' Solutions of alkalies like NaOH or KOH 
acted similarly to solutions of NaCl or KCl. All this was to be expected 
if water particles behaved as if they were positively charged, being at- 
tracted by the anion and repelled by the cation of the electrolyte. 
In tlie case of electrolytes falling under rule 2, water particles behave 
as if they were negatively charged and attracted by the cation and re- 
pelled by the anion of the electrolyte with a force increasing with the 
number of charges of the ions. Thus solutions of AI2CI6 attract water 
very powerfully, solutions of AI2 (804)3 of the same theoretical concen- 
tration act much more feebly and solutions of aluminJum citrate have 
practically no more influence on the rate of diffusion of water than cane 
sugar solutions of the same concentration. When we render M/128 so- 
