THE MICROSCOPE AND ITS PARTS. 21 



side of the field of view, it must actually be pulled 

 towards the observer's right-hand; and if the image is 

 to travel up the field, that is, away from the observer 

 as he sits at the microscope, the object must be really 

 slipped towards him, because the lenses reverse the 

 image. This seems a very complicated proceeding, 

 but it soon becomes the easiest thing imaginable. At 

 the first trial the object will be sure to leap entirely 

 out of the field, because it will be too rapidly moved, 

 and the motion is magnified as well as the object; but 

 the student will become so expert that before long he 

 will be able to make with fine needles, on the stage 

 of his microscope, complicated dissections of the 

 internal organs of the house-fly, or of some other 

 equally small insect. 



The stage will probably have two springs on the 

 upper surface, one on each side. These' "spring 

 clips" are to keep in position the glass slide holding 

 the object, unless intentionally moved. The slide is 

 put under the clips, and the object, provided it is 

 itself stationary, will remain in the field, where it can 

 be examined quietly and comfortably. 



The diaphragm should always be present. It will be 

 pierced, near the edge, with a serious of openings of 

 various sizes, to modify the amount of light thrown on 

 the object, the largest opening admitting the greatest 

 amount. The beginner will at first be disposed to use 

 too .much light; indeed this is a fault of many older 

 micro-icopists. More can be seen with a moderately 

 lighted field than when the eye is dazzled and half 

 blinded by a fierce glare. Such a blaze is objection- 

 able, not only because it tends to obscure the finer 

 parts of the object, but it may lead the student or his 



