Psrx=* 
A=480 500 520 540 560 580 600 620 640 660 
X sol. 3 pCt. 
eee Sy IL 
strated. The strong increase of gs, when approaching the limit of 
absorption (À, = 490) is again shown here very distinctly. 
The measurements will be continued with other salts. Possibly 
also the important theoretical results on the magnetic rotation 
in absorbing solutions found by Vorer!) can experimentally be 
tested by means of this method. 
Physiology. — Dr. C. WINKLER presents in the name of Dr. J. 
K. A. WERTHEIM SALOMONSON an essay, entitled: “A new 
law concerning the relation of stimulus and effect.” 
Whenever a stimulus, is applied to a biological element this fact 
will generally be followed by a stimulation-effect. In cases where a 
contractile protaplasma is concerned, the effect will consist in con- 
traction of the protoplasma. With other elements, like neurones the 
stimulation is transformed into a potential-wave, extending itself with 
moderate rapidity, some dozens of meters per second, along the nerve- 
1) Drude’s Ann. 6 p. 7134. 
23 
Proceedings Royal Acad. Amsterdam, Vol. LV. 
