396 
DR. MEYER WILDERMAN ON CHEMICAL DYNAMICS 
temperature it can also be shown that the entropy of the system changes in light. 
When chemical transformation takes place in the system this is also accompanied by 
variation in its mechanical energy. The kinetic explanation of the phenomena of 
absorption, dispersion, fluorescence, by Stokes and Helmholtz, led the author to 
the conclusion that the energy stored in the atoms and molecules under the action of 
light, partly transforms into chemical, partly into kinetic energy sui generis, which 
may be called light-kinetic energy,—a conclusion strengthened by the author’s 
experiments on the effect of light upon two plates of the same element, when they 
are immersed in a liquid, connected with a galvanometer, and one plate is exposed 
to light while the other is kept in the dark. Thus, under the action of light, the 
chemical potential of each substance increases and each substance acquires a new 
light-kinetic potential. Instead of equation (i.) we now have for equilibrium in light 
c/E + c?Ej = dE' = t' dr)' — p'dv' + y / dm{ -f- p 2 dm 2 . . . -j- \i n dmj 
+ dm y -j- \ 2 dm 2 . . . -f X n 'dm J ^ 0 . (ii.). 
Integrating this equation, then differentiating in the most general way and 
subtracting (ii.) we get 
vj'dt' — v'dp' -j- m'dky -f m'd/iy . . . J r mjdkj -j- mjdpj = 0 . . (hi.). 
General considerations show that for the system to be in equilibrium the sum 
of both potentials of each substance must be constant through the whole system, 
i.e., /a/-k X 1 '=c 1 , p. 2 ' + \ 2 — c 2 . . . (y). (iii.) and (y) give the variation of temperature 
or pressure, or of the chemical potential, or of the light-kinetic potential, or of several 
of them, with the variation of one or more of the rest of the variables. The sum of 
GE + f/E 
both potentials /x/ + X/ being = 
clrtiy 
1 ' and the equation for chemical 
reaction being tqAj + n 2 A 2 = n 3 A 3 (a), we still find that, under due considerations, 
n i (hi + X/) + % (hz X/) = n 3 (p 3 / + X 3 ').(/3). 
Taking in equation (iii.) the grammolecule as unit of mass (which is not the case in 
Gibbs’ deductions), in order to get subsequently a result which in its form and 
content expresses our present molecular conceptions of a chemical reaction, &c., we 
get, if the system is a gaseous one, consisting of one substance only, and its total mass 
is grammolecules, that the total chemical energy is p/m/, the variation in the 
same m/d/x/, the total light-kinetic energy is X/m/, the variation in the same ?n 1 / dX 1 / , 
the total mechanical energy p’v = m/RT, since pv of 1 grammolecule = ET, and 
v dp'= v'd 
rt/RT 
'H' 
/ 
the total entropy of the mass p r —my (— -j-K / ), when the entropy 
of 1 grammolecule = 
II' (of 1 grammolecule) 
-f- K'. Thus putting in (iii.) these values 
m ' 
and integrating we get /q -f ,\ 1 = RT -f RT log —~ — IT log T K' T + K", where 
v 
