d Anodisch E 
D 
Kathodisch. 
From A to C exclusively Ag(CN), is formed. At C the deposition 
of Ag (CN), on the anode begins, from C to G it becomes greater 
and greater, at ( besides the deposition of cyanogensilver on the 
anode, this compound also begins to precipitate in the liquid; at D 
the quantities of Ag,(CN), being deposited on the anode and in the 
liquid are equal, and finally from M/ to # the cyanogen. silver 
precipitates practically exclusively in the liquid. 
It is clear that in practice a current density will be worked with 
which is smaller than #. It is, indeed, possible to make the current 
density somewhat greater than /’ without Ag,(CN), being deposited on 
the anode, but this slight increase of the current density gives a 
very great increase of polarisation-tension, which can amount to 
about 0.4 or 0.5 V. A too great current density at the anode, there- 
fore, gives rise here to an appreciable loss of energy. 
Chemical Laboratory of the University. 
Amsterdam, October 1916. 
Physiology. “An evact method for the determination of the position 
of the eyes at disturbances of motion.” By Dr. C. Orro Rorrors. 
(Communicated by Prof G. vaN RIJNBERK). 
(Communicated in the meeting of October 28, 1916). 
In a communication to the Meeting of the 26°¢ of January 1916 1 
indicated, in what way it is possible to calculate the position of 
the axis round which the eye has, as it were, turned, when we 
know the abduction, deorsumduction and inward rotation, caused 
