( 345 ) 
and increment of effect, we may therefore state provisionally : 
—_dE - dR 
—_ =a —- 
dt dt 
Physical chemistry however has made us acquainted with a law 
of mass-action, GULDBERG and WAAGE’s law, stating that in a small 
particle of time the quantity of transformed matter is proportional 
to the quantity of transformable substance. Applying this law here, 
and calling the extant quantity of transformable substance Z,, we 
obtain : 
EE PE 
wherein B represents a constant. Multiplying with dtand then sepa- 
rating the variables we obtain: 
Er == Bar 2 
DM . . . . . . . a (2) 
Tr 
and after integrating: 
log nat H, =— BR-+- constant . . . . . (3) 
We may express this formula still in a somewhat different way, 
for which I choose from several motives this formula: 
LE, 
log nat —- = — BE. rua!) Law en CE] 
which may be written: 
BIS Ag BE onse vi ea eal 
A and B representing constants and « the base of the Napierian 
logarithms. 
This formula represents the quantity of transformable matter still 
extant after the action of the stimulus £. If the quantity of substance 
originally extant — before the action of the stimulus — may have 
been £,, then the quantity of transformed substance, in other words 
the effect, amounts to: 
EB Aa BR el ie die oa 
