———— eee 
~acneigionimnnnan seienoaies 
> 
Histological Preparations by Sunlight. 261 
ag obj 
diminished ; but I have convinced myself by trial that puree 8 
good pictures can be produced without it, even with very hig 
powers, a circumstance of considerable interest where motives 
— with regard to the selection of objectives suitable for 
otographic work of this kind. The power of the objective to 
e used will depend of course upon the details it is desired to 
1-8th objective may be conveniently employed to obtain 
r si dred diameters, & 1-16th 
Suitable amplifiers or even eye-pleces May be in either 
with great increase of the wer, and often 
rtain 
of definition. Still such amplifications may sometimes be ad- 
Vantageously resorted to, especially in the case of objects which 
ower. : . 
+he objective, selected deus of course be unexceptional in 
, 8 jally corrected. for 
aa aphy. It has been erroneously stated by Moitessier,* 
: in 
. 3 es . > . * 
S ee eet Appliquée aux Recherches Mi phiques, par A. Moites- 
1866, p. 180 et seq. 
