1888.] current on saturated solutions. UT 
the solutions, if always saturated, by 013c¢.c. in the case of NaCl 
and ‘11 ¢.c. in the case of KCl. 
As regards the NaCl it will be observed that the small ap- 
parent increase during the current in the quantity of salt in 
solution would be more than accounted for by the rise of tem- 
perature, but that the increase after the current stopped over 
the quantity in solution before the current began is greater than 
Storer’s data would allow. This may have been due in part to 
slight supersaturation, but is probably mainly due to experimental 
errors. The only safe conclusions would seem to be that the effect 
of the electric current must be extremely small, and that the 
application of heat slightly increases the quantity of salt required 
for saturation. Also the heat produces its effect very slowly or 
else its action is checked by the current. 
From the KCl experiments more definite conclusions can be 
deduced. Supposing the solution to have been always saturated 
the average sample taken during the current should have required 
at least 8c.c. and that after the current at least ‘2c.c. more 
AgNO, than that taken before the current passed. In the former 
case the actually observed increase was only ‘02 c.c.—really rather 
less—and in the latter case ‘08c.c. That there was a certain small 
increase in the latter case can hardly be questioned, but it was 
decidedly less than should have occurred if the solution had been 
fully saturated at the temperature when the third sample was taken. 
Considering the slightly higher temperature when the current 
was stopped this indicates that the rise of temperature would 
take a long time to produce its full effect. This, as will be shown, 
was confirmed by subsequent experiment. The increase of ‘02c.c. 
during the current is too small to rely on with certainty. Con- 
sidering that the rise of temperature was naturally fastest at first, 
and that the time the current ran was so much longer than the 
interval between the time it stopped and the taking of the third 
sample, we are led to hold, as at least highly probable, the view 
that the current retarded the solution of the salt. 
In order to judge of the effect of heat alone, the same KCl 
solution was on a subsequent occasion placed in a vessel containing 
water. This was heated so that the temperature in the solution 
rose gradually from 10° to 154° in 45 minutes. The heating being 
stopped the temperature fell to 15° in the course of 30 minutes. 
The volumes of a different AgNO, solution required for the 
titration of samples taken at these three temperatures were on 
an average 12°83, 12°96 and 13:03 ¢.c. respectively. The rise of 
temperature here is considerably greater than the average rise in 
the electrical experiments, but the quantity of salt dissolved 
during the heating is so considerable that if the heating action of 
the current had produced its natural effect the result could hardly 
