24: MICROSCOPY FOR BEGINXERS. 



rather expensive piece of apparatus, and somewhat diffi- 

 cult to manipulate successfully. But as the newest and 

 best stands have the swinging mirror, the condensing 

 lens need not be described, especially since the beginner 

 will not care to examine many opaque objects that will 

 demand stronger illumination than that of ordinary dif- 

 fused daylight or common lamplight. 



When ready to examine an object, the stand is placed 

 near the window, or, if at night, the lighted lamp is 

 stood near the instrument on the left-hand side and one 

 or two inches in front of the mirror, and the objective 

 is screwed on. The microscope is inclined at a conven- 

 ient angle ; the mirror is moved in various directions, 

 until the light is reflected from a white cloud, if possi- 

 ble, or from the lamp, onto the front of the objective, 

 where it can be easily seen. The eye is then placed at 

 the eye-piece, and if the field is but partially lighted, 

 as it probably will be, perhaps one-half of it being in 

 shadow, or only a faint trace of light visible at one side, 

 the mirror is slowly moved until the field is brightly 

 and evenly illuminated, when every part of the circular 

 bright space within the instrument is as well lighted as 

 every other part. The position of the diaphragm is 

 then changed, to be further altered, if necessary, after 

 the object has been placed on the stage. This even il- 

 lumination may at first be a little troublesome to obtain, 

 but as in so many other actions in connection with the 

 microscope, a very little practice will overcome every 

 difficulty. The fingers are soon taught; they speed- 



