302 Proceedings of Royal Society of Edinburgh. [sess. 1 
had found that aluminium conducts heat as well as silver, but I 
have been unable to find this result of Faraday’s, or any reference 
to it, in his papers. 
Note on Electrolytic Conduction. By Robert L. Mond, 
B.A. 
(Read July 10, 1890). 
At the suggestion of Professor P. G. Tait, I undertook the further 
investigation of an experiment, an account of which he communi- 
cated to this Society on Monday, the 15th of April 1878. 
In this experiment a platinum plate of moderate thickness is in- 
serted between the electrodes of an electrolytic cell, so as to com- 
pletely fill the cross-section. This platinum plate thus becomes the 
common electrode of two cells, and on perforating it it is found that 
a comparatively small hole at once changes its functions to that of 
an obstacle in one cell. 
It is interesting to study experimentally as fully as possible the 
complete chain of events from the first perforation to the total 
removal of the plate. 
The interposition of a platinum plate of the same dimensions 
as the electrodes (namely, 1 sq. cm.) reduced the strength of the 
current to about one-half. The plate was then perforated with a 
fine needle, readings being taken for each perforation. 
The strength of the current is observed rapidly to rise, the 
quantity passing through the plate rapidly and regularly decreasing; 
a transition period ensues, after which the whole current passes 
through the holes. The polarisation remains practically constant 
for the experiment as long as the area of the perforations is small 
compared to that of the plate. 
The results thus obtained were plotted as curves, the deflections 
of the galvanometer being measured along the axis of ordinates, and 
the number of holes along the axis of abscissae. 
The first curve (A) was obtained by using one central plate of 1 
sq. cm. area, the currents being obtained from storage cells arranged 
to give 10 volts, and the deflections were measured on a Helmholtz 
Tangent Galvanometer. Seventy perforations were made, each hole 
having approximately sq. cm. section. 
