CHAPTER 2 



The Use of the Microscope 



The application of the principles given in the last chapter to the every- 

 day use of the microscope is simple. It consists only of knowing what is 

 the best possible performance that may be expected of any type of instru- 

 ment and then setting it up so that it can give this performance. Broadly 

 speaking, there are three types of microscopes to be found in biological 

 and medical laboratories. These may be called, for purposes of conven- 

 ience, the "freshman microscope," the "medical microscope," and the 

 "research microscope." Let us take each of these in turn. 



THE FRESHMAN MICROSCOPE 



Specifications. The freshman microscope, of which a typical example 

 is shown in Fig. 18, is usually provided with the following features. 



Fig. 18. Freshman microscope with suitable illuminant. The microscope is an Ameri- 

 can Optical Company model No. 65 and the illuminant a simple gooseneck lamp. 



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