338 DR. MEYER WILDERMAN ON THE CHEMICAL STATICS AND DYNAMICS OF 
light. On removal of the light from the system a similar though not identical 
curve is obtained, which is the reversal of the first. It should be added that it has 
been established beyond doubt, in four different ways, that the peculiar form of the 
curves was not due to the inertia of the moving galvanometer mirror, but repre¬ 
sented the true nature of the phenomena. 
When we look away from the line which gives in the above-mentioned kind of 
curve zero deflection in the dark, we are struck by the fact that all these curves seem 
to have one characteristic course, as if under the action of light two opposite E.M.F.’s 
of two different values and with two different rates of increase were simultaneously 
produced, each of them ultimately reaching a maximum value, and on removal of the 
light the two E.M.F.’s disappear with different speeds. According as one or the 
other is more rapidly produced, the total E.M.F. starts by moving in one or other 
direction; as long as one E.M.F. preponderates over the other, the total E.M.F. 
continues in the same direction ; when the preponderating E.M.F. reaches, or almost 
reaches, its maximum, while the opposite, owing to its being produced with a smaller 
ERRATUM. 
Page 339, line 25 : for “ indicating a decomposition of 1 gramme electrochemical 
ecpuvalent in 30,000 years, read “ indicating the separation, by decomposition, of 
1 gramme of Hydrogen or of its electrochemical equivalent in 3,000,000 years.” 
only be so far a difference between the ordinary galvanic cell and our light cell, as in 
our case both the E.M.F. of the cell and the E.M.F. of polarisation are gradually and 
simultaneously produced by exposure to light, or disappear when light is removed, so 
that we cannot have as in ordinary galvanic cells one E.M.F. without the other. 
The first important result obtained from the above explanation of the peculiar 
course of the curves was thus the discovery of galvanic polarisation sui generis 
created by the action of light. In the course of the induction and deduction periods 
