FORENSIC MICROSCOPY. 131 
‘tube is placed in position and the field well lighted, a 
spectrum should be seen lying with its colored bands at 
right angles to the slit in the ocular. If the spectrum 
lines are oblique, the prism tube must be rotated until 
it bears the proper relation to the slit. 
Reference to Fig. 49 will show also a lateral tube con- 
nected with the spectroscope, into which rays of light 
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Fic. 49.—THE Microspecrroscopr. (Bausch and Lomb.) 
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from outside are projected by a mirror, and a prism 
by which these rays are reflected upward. This is used 
when it is desirable to compare the spectrum of sun- 
light with that of some object upon the stage of the 
microscope. When properly adjusted the two spectra, 
produced respectively by light passing up through the 
microscope and by that reflected through the side tube, 
will appear to lie side by side. 
