CHAPTER II. 

 THE MANIPULATION OF THE MICROSCOPE. 



I. Setting Up the Microscope. — The microscope is 

 an instrument of precision whose deUcacy may be easily 

 impaired by carelessness or neglect. When not in use 

 it should be protected from dust by placing it in its case 

 or under a bell-glass, and any particles which settle 

 upon it should be removed with a camel's-hair brush 

 and chamois-skin. If necessary, the mechanical parts 

 may be first cleaned with chamois-leather moistened in a 

 solution of equal parts of benzine and olive-oil and then 

 wiped with dry chamois. 



The microscope should be handled always by the base, 



and not by the upper part of the pillar, in order to avoid 



straining the fine adjustment. When in use it should be 



placed on the work-table rather near the edge, with the 



pillar side nearest the observer, who should sit close to 



the table in a chair of such height that his eyes will be a 



little above the level of the upper end of the draw-tube 



(see Fig. 17). Those unfamiliar with the microscope 



are apt to sit too far off or too high above the instrument 



and bend painfully toward it. For general work it is 



best not to tilt the tube of the microscope even when the 



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