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PRACTICAL PHOTO-MICROGRAPHY. 
Illumination by Reflected Light. 
Objects are sometimes of such a nature, or mounted 
in such a manner, that they must be examined, and 
photographed, by reflected light; and frequently photo¬ 
graphs of such objects are both beautiful and valuable. 
At various times various instruments have been used 
for this kind of illumination, but we need refer to only a 
few, as the others have been superseded by later and 
better appliances. 
It is assumed that the obiects are either mounted on 
j 
some opaque ground, or have some opaque material 
Fig. 29. 
placed behind the ordinary mount. The first method 
that will suggest itself is to use some low angle con¬ 
densing arrangement, such as a bull’s-eye, above the 
stage. This may be done. The plane side of the 
bull’s-eye is presented to the object, and the light and 
the bull’s-eye are so arranged that the light is brought 
to focus on the front of the object. The light and 
bull’s-eye should be placed as near to the tube of the 
microscope as convenient, and it will be seen that this 
system is available only for low powers where there is 
plenty of room between the front of the objective and 
