of Photography to the Microscope. 191 
those obtaine enam with a ;'sth of 180° aperture. Por- 
tions of the negative bore a photographic enlargement of 10 
diameters. Mr enam announces* that he has discovered by 
be used when it is found desirable. 
By arranging the apparatus according to the plan adopted by 
Prof. y. Kobell in his micro-stauroscope, (this Journal, [2], vol. 
XiX, p. 425), the peculiar effects which microscopic crystals ee 
duce on the cross and rings of calc spar, can be photographed. 
By removing the conde and objective, as well as the slide con- 
taining the crystals, beautiful photographs can be obtained of the 
while j in ¢ f ‘the normal cross and ring; 
oi x phowpgrap>e > but so far as I know this is ke 
* Quart, Journal of Mic, Science, No. xxi, p. 145. 
