Mi. A. K. T'ltton. A C> ij 



Comparison of the Optical Ellipsoids. 

 Optical Indicatrix. 



a y Double refraction. 



KXn scluiJitc 0-9960 : 1 : 1-0101 141 



Kl./n 0-9961 : 1 : 1-0072 111 



CsZn 0-9977 : 1 : 1-0033 :>; 



KZn selunate 

 RbZn . 



I'sXli 



Optical Velocity Ellipsoid. 



a b c 



1-0040 : 1 : 0-9900 



1-0039 : 1 : 0-9929 



1-0024 : 1 : 0'9968 



140 



110 



56 



Comparison of the Optical Indicatrices when ^K7.n= 1. 



a y 



0-9960 : 1 : 1-0101 



1 -0099 



KXn 



28 



27 



IJhZn 



CsZn 



0-9988 



108 



1-0096 



1-0027 



1-0119 



92 



The last series of ratios shows the total change of the ellipsoid ou 

 passing from one salt to another, and the numbers are obtained by 

 considering the initial length of the /3 axis, that is, its length in the 

 potassium salt, as unity. They are graphically expressed by the 

 dotted curves in fig. 3. 



FIG. 3. 



HNM IOCS 1010 



Axial ratios of optical indicatrix. 



