1G2 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
then transferring them to the slide, which has previously been coated 
with albumen and glycerin. The sections are then dried by pressure 
between blotting-paper, the wax is melted, removed by xylol, and the 
sections aro then mounted in Canada balsam. 
For some time before Dr. Gaskell published this method I had been 
using it, and had experimented with several modifications of it; one of 
these has been so successful in my hands, and in those of others to 
whom I have communicated it in this laboratory and other laboratories 
in Edinburgh, that I am desirous that it should become more widely 
known. 
In using albumen and glycerin as a fixative, according to Meyer’s 
method, which is, I suppose, the way in which Dr. Gaskell employs 
them, I have met with objections which made me wish to omit that part 
of the process. These difficulties are : — That it is not always easy to 
get the layer of albumen and glycerin of equal thickness all over the 
slide, so that the sections do not lie quite flat ; that patches of coagu- 
lated albumen sometimes retain stains, especially some of the anilins, 
in a disturbing manner, and this inconvenience, I am told, is specially 
felt in microphotography ; that in manipulating sections on the slide, 
solutions of picric acid, moderately strong alkaline solutions, and some 
other fluids cannot be used, as they loosen the adhesion of the section to 
the slide. Further, I have found, in using Dr. Gaskell’s method, that 
if a very large number of sections are to be mounted on one slide, the 
fixative is apt to be washed off ; and if one trusts to the fixative after- 
wards, and proceeds in the usual way as described by him, some of the 
sections may be lost. The method I use is the following: — 
The piece of tissue is imbedded in paraffin in the usual way, and I 
will suppose that a complete series of sections is desired, and is to be 
cut with the Cambridge rocking microtome. The paraffin block con- 
taining the tissue must be trimmed very carefully, care being taken to 
see that the surface meeting the razor is exactly parallel to the opposite 
surface, and that the block is exactly rectangular. A thin layer of 
soft paraffin is then applied to the surface meeting the razor and to 
the opposite surface — this is best done by dipping these surfaces into the 
melted soft paraffin — and when this has become firm the surfaces are 
again trimmed square. The reason for this very special care is that 
any curve in the ribbon, produced by neglect of this precaution, is 
accentuated by the flattening out of the sections, and though in mounting 
several ribbons on one slide a slight curve does not matter, and can, 
indeed, be corrected by folding up the soft paraffin between the sections, 
a sharper curve of course interferes with the regular disposition of the 
series. When all the sections required have been cut, the ribbon must 
bo divided wdth a sharp knife into lengths corresponding to that of the 
slide in use. A very convenient size is a slide of 4 by 2 in. with a 
cover-glass of 3 by 1^ in. These ribbons are then to be seized at one 
end with forceps, and the other end is gently lowered on to the surface 
of the warm water, and as the sections flatten out they will be found 
to move along the surface of the water, so that more and more of the 
ribbon can be lowered. It is not so satisfactory to hold both ends of the 
ribbon and lower the middle first. When the flattening is complete, 
the slide, carefully cleaned, is immersed in the water, the ribbon is floated 
