(6545 
constant ‘currents; it is not necessary therefore to regard this tetanus 
as caused by polarisation. 
Constant stimulation of sense-organs. For stimulation of muscle, 
the views expounded just now, may be proved right in a very simple 
manner. For that purpose we only need to measure a number of 
tetanus-curves, taken under different circumstances, and to test the 
results to our formula. Indeed I intend this to be my first task, 
immediately after publishing this very succinct, theoretical paper. 
But the matter becomes far iess simple whenever sense-organs are 
concerned, because in that case it is impossible to give an objective 
representation of the intensity of a stimulation-effect. We cannot 
here do more than search for facts, to support the once established 
theory. For the moment I will confine myself to the following 
facts. 
Har and eye. According to our theory in the case of very feeble 
stimuli being used, an increment of effect will be observed when 
the stimulus begins to act. Practically this is an acknowledged fact. 
It has been discovered repeatedly, and is known well enough espe- 
cially to those who have occupied themselves much with X-rays. 
If a thoroughly reposed eye begins to regard a radioscopic image 
on a fluorescent screen, it will see indeed the whole of the screen 
illuminated, but only after a few seconds it will begin to distinguish 
the image more clearly. (This fact must be distinguished from 
the improvement of sensation acquired by the non-reposed eye in 
regarding a fluorescent screen, this improvement being achieved far 
less rapidly). 
URBANTSCHITSCH found also that feeble tones of a tuning fork were 
not immediately heard in full intensity, but that it needed therefor 
a certain space of time, dependent on the intensity of the sound. This 
space of time may amount to 1 or 2 seconds. In the Röntgenroom 
1 observed repeatedly that a space of time from 1—3 seconds was 
needed to obtain with the well-reposed eye a good sensation of a 
feeble fluorescent image. These facts were regarded hitherto as 
“Bahnungserscheinungen.” Probably it is partly through this summation 
too that must be explained the long latent period in the case of 
feeble stimuli of temperature acting upon the skin. And in all 
probability in the same way the summation of feeble stimuli of touch 
causes the sensation of titillation and may lead to a tickling-reflex. 
The feebler the stimuli the more time will be the prominent 
feature. 
Finally we can deduce from our formula an expression for restor- 
ation of fatigue. Researches concerning this point have been made 
ade mat 
