PROF. DR. F. M. JAEGER. Epe! 
A NEW PHENOMENON, ACCOMPANYING THE DIFFRACTION OF RÖNTGEN-RAYS 
IN BIREFRINGENT CRYSTALS. 
+ 
a“ 
Fig. 6. 
Fig. 5. Dextrogyratory Sodium-Ammonium Tartrate (4 H30). 
Dextrogyratory Sodium-Ammonium Tartrate (4 H90). Plate perpendicular to the 6 - axis. 
Plate perpendicular to the a - axis. 
, Ld 
; 
; ‘ae 
: 
; x 
6 *f ; 'e 
1 Ld , ® 
® ’ . A 
é 
- En 7 
we 
| - ad « 
d 
A tie cab " 
EE" ‘ 
Fig. 7. Fig. & 
Hambergite ; plate perpendicular to the a-axis Hambergite ; plate perpendicular to the b-axis. 
d = 1.56 m.M.; A = 50 m.M. d = 1.54 m.M.; A = 50 m.M. 
roceedings Royal Academy Amsterdam Vol. XVII. HELIOTYPIE, VAN LEER, AMSTERDAM 
