2 MICROSCOPY FOR BEGINNERS. 



to each other, but close to the object, the combination 

 acting as if it were a single lens, the magnifying power 

 being much greater than that of but one glass, and the 

 distance from the object much shorter when in focus. 

 In the compound microscope the lenses near the eye 

 magnify the image formed by the lower glasses, and 

 that image is inverted, the upper side of the object then 

 appearing to be the lower, the right-hand side the left, 

 and the left-hand the right. In the simple microscope, 

 however, the image is not inverted ; and in those forms 

 where two or three lenses are combined, the effect is the 

 same as though one glass of great magnifying power 

 were used. But separate the lenses so that the upper 

 shall magnify the image produced by the lower, and you 

 have a simple form of compound microscope. In the 

 simple microscope we see the object itself, in the com- 

 pound we see the enlarged image of the object. 



As a simple microscope does not seem to invert and 

 reverse the object, and because the distance between the 

 two is long when a low-power glass is in focus that is, 

 when the glass is in such a position that the magnified 

 object looks clear and distinct to the eye it is always 

 used for the examination of a flower, the surface of a 

 piece of bark, a stone, an insect, or any other specimen 

 of considerable size, or one that is visible to the naked 

 eye, more extended study being reserved for the com- 

 pound instrument at home. A simple microscope, a 

 "pocket-lens" as it is often and preferably called (Fig. 1), 

 is really indispensable to every one who has a taste for 



