528 PROFESSORS A. W. RETNOLD AND A. W. RUCKER ON THE 
Current from 20 cells sent up the film ; 
(2) T = 484 /x./r. r = 1'69, 
332 „. 1-81, 
314 „. 1-90, 
White. 4-19. 
Current sent up and down the film in turn : 
(3) T = 320 /x./x. r=178, 
307 „. 1-84, 
296 „. 1-98. 
Film began to thicken spontaneously : 
(4) T = 314/x./x. r=2-07. 
An upward current was next applied and the film allowed to thin with the 
following results : 
(5) T = 388 )a./x. r=l-60. 
White. r = 4'47. 
It will be noticed that every time the film was disturbed the value of r fell, i.e., 
the specific conductivity of the film was reduced more nearly to that of the liquid in 
mass, nor was this merely due to the fact that the first effect of the currents was in 
every case to thicken the film, the value of corresponding to a given thickness was 
always less in a more recently disturbed film. This is proved by comparing the 
values of r corresponding to 320 /x./x. in groups (3) and (2), and those corresponding 
to 388 /x./x. in groups (5) and (2). 
We take it that this is sufficient proof that though the phenomenon we are 
studying depends on the thickness, it is not merely an explicit function of the 
thickness of the film, i.e., is not due exclusively to a peculiar molecular constitution 
depending on the thickness. If this were so, the molecular conditions peculiar to a 
particular thickness would be immediately re-established as soon as the film regained 
that thickness after disturbance. 
We think that the next step should be to try to separate the effects due to the 
pellicle and to the capillary forces if both co-exist. The pellicle is possibly due to 
chemical actions between the liquid and the atmosphere. An apparatus is in course 
of construction which will enable us to exjjeriment in other gases more satisfactorily 
than hitherto. For the moment we venture to lay our results before the Society 
without a full explanation. 
We believe that the main fact, viz., the change in the conductivity of an unsalted 
