12 MICROSCOPY. 



image is formed at the conjugate focus and hew this image is mag- 

 nified by the eye-piece, thus producing the magnified, inverted, real 

 image which is viewed by the eye of the observer. 



MANIPULATION AND CARE OF A MICROSCOPE. 



Handling. 



The microscope should be handled with more than ordinary care. 

 In moying it from place to place it should be caught firmly by the 

 pillar. Reagents of any kind should not be allowed to come in con- 

 tact with it. Alcohol will destroy the lacquer, and acids will pro- 

 duce corrosion of its surface. The hands, therefore, should be kept 

 perfectly clean. 



Cleansing. 



The microscope may be cleaned with a linen cloth. Reagents 

 should not be used in cleansing the objectives and eye-piece without 

 the direction of the teacher. To remove balsam from the objective, 

 alcohol or xylol may be used, but should be quickly removed with 

 Japanese paper, a soft paper especially used for cleaning lenses. 



Obtaining a Focus. 



To obtain a focus, place the slide upon the stage so that the ob- 

 ject to be examined appears in the center of the aperture; adjust the 

 reflector so as to illuminate the object. Lower the objective by 

 means of the coarse-adjustment until it is below the focal point; 

 then, with the eye at the eye-glass, work upward until the object ap- 

 pears, making the focusing perfect by means of the fine-adjustment. 



Cautions. 



To save harm to the eyes in the use of the microscope it is a good 

 plan to keep both eyes open; let the eye be used as though viewing 

 some distant object; there should be no conscious strain to obtain a 

 focus, but let the hand with fine-adjustment aid the eye ; do not use 

 the microscope long at a time, so as to produce an aching sensation 

 in the eye. 



Allow nothing to touch the lenses, except Japanese paper or soft 

 linen, which may be used in cleaning them. 



