CARE Of flPPflRATUS. 



It is very desirable that the student should have had some 

 previous training in microscopical manipulation, but to those who 

 have had no such opportunity some few explanations and sugges- 

 tions are necessary before they can work to advantage with so 

 delicate an instrument as the compound microscope. Access should 

 be had to some of the excellent books on microscopical technique 

 mentioned elsewhere in this manual. 



With reference to the care of the microscope it is especially 

 important that the optical parts be kept free from dust or dirt, and 

 in any case where the lenses come in contact with anything that 

 would soil them they should be cleaned at once. The Japanese 

 bibulous paper recommended for this purpose can be secured of 

 G. S. Woolman, 116 Fulton street, New York. After cleaning a 

 lens, the soiled paper should be thrown away or it may be used for 

 removing liquids from any part of the instrument. Since the glass 

 from which the lenses are made is quite soft, it should never be 

 subjected to any hard rubbing, as its surface would be injured by 

 scratching. Never touch any of the glasses with the fingers or 

 allow the objective to come in contact with reagents or stains that 

 may be on the table of the microscope. If balsam or shellac should 

 get on the face of the lens, wet it with alcohol and remove at once 

 with a linen cloth as the alcohol would soon injure the mounting. 

 Glycerin and glycerin jelly can be removed with water. 



Many of the operations in testing for different vegetable or 

 mineral substances must be performed on the stage of the micro- 

 scope, where the action of the agent can be determined. In 

 this case, much care must be exercised in order that the 



