THE Microscope. 61 
Since it can be used without special apparatus other than a cell 
for solution of sulphate of copper. The camera differs from all 
Continental or other models, in its lightness, its easy adjust- 
ment anywhere from the horizontal to the vertical, and the 
manner of supporting its weight upon an immovable part of 
the microscope instead of upon the body, so that it can not by 
its weight change the focus during manipulation. The first cost 
is small, and the working expense Jess than that of any other 
form. In order to insure satisfaction, the apparatus should be 
well made. There are some in the market having serious de- 
fects, such as imperfect joints whereby extraneous light is ad- 
mitted. In the illustration, the instrument is shown ready for 
use: A, is the camera box wherein may be concealed a 
shutter; B, is the brass cone; C, is the collar through which 
2 
