1 



REVIEW OF THE DATES CONCERNING THE HERE STUDIED SALTS OF BERYLLIUM. SCANDIUM, IRON AND INDIUM. 



I ' Indium-ethylsulphate \ Monoclinic 



Observed Forms. 



and red light. Strong dispersie 



I BeryUium-ethytsuIphi 

 ' (Spec. Weight 



c(,«=l.857;it i; 



salt : BeO . Be (SOj 



C2Hs)2 + 4H20 





6 I Ferrhacetylacetonate 



1 Beryllium acetyh 



") After measurements of V. 



; 1 lOnj Optically uniaxial, of negativ 



■ j There is no relation between the 



= 1.413 and n^ =1.4:15. > crystallonomical character of Ihissalt 



Very strong birefringence: about | ^"'^ ^^^ previous ones. 



0.04. ; 



J 1101 ; jOlOi ; [UÜI 1 



The plane of the optical axes is 

 } 100 j ; small axial angle; birefringen- 

 ce: + ; dispersion: ■-<v. 

 0011 ; I no; ; [010} The plane of the axes is [ 100 { . 

 I Very small axial angle; birefringen- 

 ce: -f; dispersion: ^ < r. 

 Planeoftheopiicalaxesis [ 100 }; the 

 axial angle is about 50°, for Li- 

 light; negative birefringence. 



Very remarkable dispersion of the 

 axial planes for blue and red light; 

 very strong dispersion of all bisec- 

 trices. The crossing of axial planes 

 ind the change of first and second 



These three salts are perfectly iso- 

 lorphous with each other; the 

 " ' very probably 



salt and the preceding < 



