( 647 ) 
BAMBERGER where the investigated substances generally contained 
one or more CH; groups next to OH. 
It should also be pointed out that in tribromo-mesitylene the Br 
atoms may be replaced by NO, while dimethylmesitylene yields 
dinitro-mesitylenenitramine with NO, groups in the meta-positions. 
(Krossre 5). 
The particulars of this research will be published in the , Recueil”. 
Physiology. — “On the effect as a time-function.” By Dr. J. 
K. A. WeRTHEIM SALOMONSON. (Communicated by Prof. C. 
WINKLER). 
(Communicated in the meeting of March 29, 1902). 
In the course of three former communications we have considered 
the relation between the magnitude of effect and stimuli of different 
intensity. In its strictest sense the law there formulated by us, is 
valid only in cases of momentaneous stimuli, where the effect appears 
after the stimulus has ceased to act. 
The following essay will consider the manner in which an effect 
proceeds — the way it changes perpetually from one moment to 
another, whether under the influence of momentaneous stimuli or of 
lasting constant stimuli. 
Considering the effect as being due to the transformation of chemical 
substance, we may admit with GULDBERG and WAaGzs that the rapidity 
of this transformation will be proportional to the available quantity 
of transformable substance. If the amount of the latter may be 
represented by W, then: 
ete) LL ML EE eer U 
Now let us examine what will be the amount of this quantity 
W in general. Firstly we may admit that at the moment ¢ there 
is in store a certain quantity of transformable substance P. 
But we are dealing with living protoplasma. 
After activity of the protoplasma we know that products of 
fatigue will have been formed. These will gradually disappear and 
be replaced by fresh substance. In general it is a most plausible 
supposition that the quantity of new transformable substance sup- 
1) Rec. 6, 31. 
43 
Proceedings Royal Acad. Amsterdam. Vol. LV. 
