Appendix I 
THE MICROSCOPE 
A MicroscoPE is an optical instrument, consisting of a lens, or 
combination of lenses, for making an enlarged image of an object 
which is too minute to be viewed by the naked eye. 
Microscopes .are of 3 principal kinds, viz.: simple, dissecting 
and compound. 
THe SIMPLE MICROSCOPE 
This consists simply of a convex lens or several combined into a 
system and appropriately mounted. A good example of a sim- 
Fic. 490.—A dissecting microscope. Description in text. 
ple microscope is a reading glass. This type of simple micro- 
scope is valuable in field work, in the examination of dried 
herbarium material or the external characters of crude drugs, 
where only a low magnification of the object is required. 
Tue DissEcTING MICROSCOPE 
But when flowers or other plant parts are to be dissected, it is 
necessary to have both hands free. To meet this need various 
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