MICROSCOPICAL LABORATORIES, I 87 


the prism from sliding down if the glycerine does not hold it well. 
The microscope should now be arranged so that the source of light 
will be as nearly as possible at a right-angle to the axis of the tube. 
If the stand is a low one it may be raised on a cigar box. Place 
the lamp about a foot from the centre of the stage, on the left, 
with the edge of the flame toward the stage. Then introduce a 
small condensing lens, and focus the flame carefully upon a piece 
of white paper placed upon the stage. Then put on the slide, 
with the prism attached, and it will not be difficult, by slight 
changes in the position of the lamp or bull’s-eye, to make the lines 
visible, 
It is much more easy to make a resolution in this way than by 
using the mirror. It is necessary to have a sharp point of light 
upon the object in order to get the best resolution, and if the mirror 
is used it should be carefully focussed upon the object. However, 
a large mirror is very difficult to use in this kind of work, for there 
is a flood of light from it, which is detrimental to good resolution. 
—American Monthly Microscopical Journal. 

MICROSCOPICAL LABORATORIES. 
By H. Harcn, M.D. | 
ie the February number of the JouRNAL, there is an article by 
Dr. J. W. Crumbaugh, in regard to which I would like to offer 
a few words. Many of his suggestions are good, but in some 
respects I would beg leave to differ with the writer. Dr. Crum- 
baugh’s idea is to surround the student with altogether too much 
and too expensive paraphernalia, which has a tendency to discourage 
him at the start. It has been my experience, and is also taught by 
the leader of pathological science, Virchow, that the more simple 
the microscope the better. Better work can be done without fancy 
rack stages and a multitude of screws, as has been illustrated by 
some of the work done by students under Prof. Bunker, of L. 1. 
Hospital Medical College. In place of Queen’s revolving table, I 
much prefer tables made square or long, of heavy, polished wood, 
well oiled, and fastened firmly to the floor. It has always seemed 
rather strange to me why some microscopists prefer artificial to 
natural light ; the former is much more trying to the eyes, and, ac- 
cording to my idea, for general work it 1s not so good. I would 
have the light come in from only two sides, east and north. The 
material for the student to examine should always be as fresh as 
possible, and when pathological, the history of the case as known 
le 
