•2664 



Journal of Applied Microscopy 



With a very strong light, the solution may have a rather deep blue color ; with 

 a less powerful light, the solution must be weaker. 



In studying the extremely difficult achromatic structures concerned in nuclear 

 division, a light violet solution of permanganate of potash is a good filter if the 

 preparation has been stained in violet. Similarly, various filters may be used 

 according to the staining of the more critical structures. 



The Welsbach lamp furnishes an excellent light. It should be placed so that 

 the rays will be focussed upon the mirror of the microscope. Some of the more 



Fig. 1. 



powerful acteyline bicycle lamps are quite satisfactory. The Argand type of 

 gas light is good, but will usually need a reflector behind it. A kerosene lamp 

 must also be reinforced by a reflector. The old fashioned silvered reflector, 

 still used in country churches and halls, will do, but is hardly equal to the cheap 

 reflectors of shorter focus which are so commonly used with incandescent electric 

 lights. The incandescent electric light itself has not given satisfactory results. We 

 have not tried the electric arc, but it would no doubt be satisfactory, if tempered 

 by ground glass. It would probably be worth while to try the Nernst light. 



