80 KESEAKCH IN THE USE OF THE MICROSCOPE 



object with different apertures in the condenser when a proper 

 compensating apparatus for keeping the intensity of the light the 

 same with all apertures in the condenser is employed. Neither has 

 there been sujSicient attention paid to the question of increasing or 

 reducing the brilliancy of the illumination without varying the 

 aperture of the condenser. 



In metallurgical work, the method of throwing the light through 

 the object glass on to the object is undoubtedly very effective, but 

 every convex surface that the light meets in passing through the 

 object glass must of necessity throw back a proportion of the light, 

 thus fogging the final image. There is room for research as to 

 another means of illuminating the opaque objects to eliminate this 

 element of flare and ghost images. 



This short paper is written to indicate by a few suggestions that 

 we are more likely to obtain real advances in microscopy by setting 

 up researches on the use of the instrument than by devoting the 

 whole of our time to the discussion of the mechanical details of a 

 slow motion or the most convenient diameter of a milled head. I 

 cannot believe that we are likely at the present time to find a 

 body of disinterested amateurs, with the required scientific training, 

 to take up these difficult subjects. The subjects I have mentioned do 

 not begin to cover the field of research that is required, and if this 

 meeting could be made instrumental in the inauguration of this 

 class of research, it will have accomplished an extremely valuable 

 piece of work. 



