6 HOW TO USE THE MICROSCOPE 



one being suitable for iitting into a dissecting micro- 

 scope, the second for the pocket, and the third 

 being a combination momit, which can be used 

 either for the pocket or as a dissecting lens. With 

 this firm's lenses the magnifying power ranges from 

 6 to 20 diameters, and the price in nickelled pocket 

 mounts for any power is 12s. 6d. Aplanatic mag- 

 nifiers are made by all the leading manufacturers. 

 If the price is not too serious a consideration, I 

 should certainly advise the reader who desires the 

 best available pocket lens to purchase an Aplanatic 

 by a good maker. 



A pocket magnifier of any type permits the 

 obvious advantage of great freedom in its use. It 

 can be held at any angle, and be used anyvi^here 

 where there is a sufficient light. The fullest advan- 

 tage can be taken of such light as is available, and 

 the lens is compact and portable. Carried in a 

 vest pocket, it is at hand in any emergency. Of 

 course, it cannot give the magnification of a com- 

 pound microscope, but a good worker will always 

 use it in preliminary observations of objects which 

 are to be prepared, wholly or in part, for examina- 

 tion under higher powers. 



Pocket magnifiers are of sufficient power for pur- 

 poses of dissection of various objects. The mag- 

 nification they give is usually sufficient to enable 

 the student to make clean and satisfactory dissec- 

 tions of flowers, insects, and other objects too 

 numerous to detail. But to make dissections both 

 hands must be free, and to secure this freedom the 

 lens must be fixed in some kind of a stand ; so fixed, 

 it becomes a dissecting microscope. 



