226 
PAINTING SLIDES FOR THE MICROSCOPE. 
Oct., 1890. 
wards, finishing as I go on. It is not difficult to get washes 
of colour perfectly even, if, after they are dry, you breathe on 
them, and “ dab ” them all over with a soft brush. 
You cannot put in the details first and a wash of colour 
over them, because this would smear everything, and the 
great secret of painting in water colours on ground glass is to 
use as little water with your colours as possible. When I 
began I worked my colours too wet, and the slides I paint now 
are much better than my first. The high lights can be picked 
out with a moistened brush, and anything you want to alter 
can easily be washed completely out with a brush, without 
disturbing the rest of the drawing. It is difficult to do this 
on paper, but it is quite easy on glass. I may remark that 
fine lines need a brush with a very perfect point, so I keep at 
least two in use—one for general work, and a newer one with 
uninjured point for the fine parts. 
At this stage a few notes on the colours will be useful. 
Lamp-black .—A good colour, transparent when put on 
thinly. It works well, and will make very fine lines. That 
in tubes is best. 
Paynes Gray or Neutral Tint .—Invaluable. It is trans¬ 
parent, makes fine lines, and is good for dark backgrounds. 
It should be used from a tube. 
Prussian Blue .—Very good, but it will not do for dark 
backgrounds. 
Sepia .—Transparent, a very nice colour, but it is difficult 
to make fine lines with it because it is so gummy. It will do 
for dark backgrounds. 
Burnt Sienna .—Very useful. 
Raw Sienna .—This looks on the slide as if it were verv 
%/ 
transparent, but on the screen it is found to be more or less 
opaque. If used at all it must be put on very thinly. 
Crimson Lake .—No other crimson does so well. I hope it 
will not fade as it does on paper. 
Chinese Orange .—Very nice but useless, because it fades 
quickly. 
Scarlet .—Alas, there is none ! Crimson lake and burnt 
sienna do pretty well. 
Greens .—I know of no good ones. Most greens are either 
opaque, or, if transparent, when they are varnished all the 
vellow washes out, leaving the slide blue. 
Yellow .—Gamboge is good, but the varnish washes it out 
unless it is mixed with gum. Indian yellow fades, and so is 
useless. 
When looking through the microscope, the uninitiated 
alwavs like “ dark-field illumination,” and tliev like it in 
