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SUMMARY OF CURRENT RESEARCHES RELATING TO 
tried the oil of cajeput was the difficulty to mount neatly and evenly 
sections of human skin and tracheae, for they curl up when placed in 
alcohol. This oil is better than clove oil for this purpose, but un- 
fortunately alcohol has to be used, though the process is simplified by 
using it diluted. I hardly know of the specimens for which I have 
been compelled to use absolute alcohol, the ordinary spirit being 
sufficient. In England where methylated spirit is the chief dehydrator 
used on account of cheapness, then you may require to use absolute 
alcohol. The only cases in which I have used the last have been 
where I was making cover-glass specimens of bacteria, and was in a 
hurry for them to dry so that I could mount at once. Neither is it, 
I believe, used in the University of Michigan in the histological depart- 
ment. I find my mounts perfect, even those stained wdth auilins after 
some four years, and in a paper written in one of the journals of 
microscopy I casually mentioned it with some other clarifying agents. 
Turpentine and creosote are used by many to get over the difficulty of 
strong alcohol ; these are very good, but personally I object to the 
penetrating odours. I would like to say that I think a great deal of 
difficulty is made over mounting in balsam, which in reality never or 
seldom exists. True, each method is not nearly so difficult on practi- 
cally demonstrating as by reading. I give you the method I have 
always employed for myself and also for teaching, with success so far. 
Have a mounting card made so that you can use it to centre the slip. 
In the centre of the slide place a medium sized drop (the second which 
falls off the rod is about the size) ; carefully spread the balsam over 
the surface not quite to the edge of the cover (when it may have been 
placed in position). Lift the object from the clove oil, drain off most 
of the oil, except in such sections as lung, brain, &c., and transfer it 
to the slide in such a way that it is in the centre when mounted, and 
do not draw the lifter beyond the ring, or the medium runs a little 
outside the cover and makes an untidy mount. See that the sections 
have no folds, then take a clean cover-glass in the forceps, and near the 
edge of it let fall a drop of balsam, invert the cover, and place the point 
of a needle on the slip at about the place where the edge of the cover 
is to be when mounted ; place the edge of the cover-glass against 
the needle and gently lower it till the drops meet and flow evenly ; 
when the balsam gets to about the middle of the specimen, slowly 
draw away the forceps almost parallel to the slip and the cover is then 
in place, with few, if any, air-bubbles under it. Do not press down 
the cover with a needle or weight, for unless you have a quantity of 
superfluous balsam it is not necessary ; put the slip away in a warm 
place in a tray or cabinet, perfectly flat, and in drying the balsam con- 
tracts and draws down the cover to the specimen. I often ring slides 
at once with Hollis’s glue, even sending them by post 200 to 500 miles 
without the least harm. The two essentials are to learn the amount 
and thinness of the balsam, and not to leave too much clove oil on the 
lifter. Drying of objects in ovens, &c., seems to me a nuisance, except 
in cases of mounts without pressure, and even here I do not advocate 
it. The formula that I use for balsam may be useful, as it is colourless 
w’hen mounted and easily made; otherwise the Palmer Slide Company’s 
balsam is the whitest that I have bought of late years, and is a quick 
