﻿55-i Dr. H. W. Malcolm on Double Refraction in 



cathode was about 2 mms. high (see fig. 3 for the case of a 

 cube of gelatine with electrodes touching the centres of 



Fiff. 3. 



opposite faces). At the anode came a hole full of liquid ; 

 round about the jelly had a deeper tint, as also at the outer 

 boundary of the swelling at the cathode ; these places were 

 harder than the surrounding jelly, and had suffered a loss of 

 water or gain of* gelatine. Sometimes the swelling at the 

 cathode was radially striped or showed a network of fine 

 cracks ; with the microscope could be seen drops of liquid 

 oozing out at the crossing of two cracks. On standing these 

 lines disappeared, and the rings round the anode lost their 

 sharpness ; displaced water had been restored by diffusion. 



The displacement of the central line in the compensator is 

 shown in fig. 4. At the anode it increases, from the centre 



Yw. 4. 



out, to a maximum at the first hemisphere or inner edge of 

 the furrow, then through zero to a maximum in the opposite 

 direction at the second hemisphere or outer edge of the furrow; 

 at the inner edge ihe dilatation is negative, at the outer edge 

 positive, parallel to the radius. At the cathode the displace- 

 ment indicates a negative dilatation parallel to the radius 



