1888.] Mr W. Peddle on Tmnsition-Eesistance. 123 
motive force of polarisation. The results are given below. The 
last interval of break was 1 minute. All the other intervals were 
half a minute. 
Experiment 2h, 
Deflection. — 3*60, 3’10, 2-84, 2*60, 2*45, 2*34, 2*20, 2T2, 
2-04, 2-00, 1*92, 1-87, 1*82, P78, P74, P70, P70, 
1*60, 1-56, 1-52, 1-49, P47, 1*44, 1*42, P40, P38, P36, 
1-37, 1-34, 1-32, 1-30, 1*28, P26, P25, 1*24, P23, 
1-22, 1-21, 1-23, 1-20, 1-19, M7, M6, M5, M4, 
M3, M2, Ml, 1-10, M3, Ml, MO, P09, 1*08, 
1-07, 1-06, 1-06, 1-06, 1-05, 1-04, P07, 1*05, P04, 
1-03, 1-02, 1-02, 1-01, 1-01, 1-01, 1-00, 1-02, POl, 
1-00, 0-99, 0-99, 0-98, 0-98, 0*97, 0*96, POO, 0-99, 
0-98, 0*97. 
In order to explain the increase of capacity, Varley {Proc. Roy.. 
Soc., 1871), supposed that there was a film of gas separating the 
plate from the liquid, and that this film was compressed by the 
tendency of the oppositely electrified surfaces to approach. Since 
the electric attraction is inversely as the square of the distance, he 
supposed that the molecular forces keeping the particles of the gas 
apart were inversely as the cube of the distance. I do not think 
that his supposition of compression is necessary; but, as he does 
not enter into detail regarding his method of experimenting, a 
conclusion cannot be easily arrived at. However that may be, 
the phenomena exhibited in experiments 2a and 26, merely show 
that electric absorption is occurring in the one case, and that 
residual discharge occurs in the other. The insulating portion of 
the circuit consists of two parts, — the gaseous film which conducts 
appreciably, and the space between the gas and the plate, across 
which no conduction can occur so long as decomposition does not 
take place. Thus Clerk-Maxwell’s theory of a composite dielectric 
applies to it, and shows that electric absorption and residual 
discharge must occur. The oppositely charged layers of electricity 
are not separated merely by the molecular distance between the 
gas and the plate until conduction has taken place through the 
gaseous film. This fact has important bearings on all determinations 
of the capacity of electrodes. 
I give below the results of an experiment on the discharge of 
