ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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previously prepared, are inserted ; one end of the spring is attached to 
a cork stopper and then lowered into a broad-necked bottle containing 
the solution. Of course several bottles with different reagents may be 
used ; for example, in staining flagella of bacteria, one bottle may hold 
the mordant, another the stain, and so on. 
Mounting large Sections of Vegetable Preparations.* * * § — Dr. H. 
Schenck mounts large sections in the following simple manner. The 
sections are placed for 24 hours in a mixture of equal parts of 
spirit and glycerin. They are then transferred to pure glycerin until 
they are perfectly saturated therewith. This takes at least some hours, 
and it is well to let the preparations soak for a whole day. The sections 
are then removed and carefully dried between folds of blotting-paper, 
so that all the superfluous glycerin is removed. The next step is to pour 
some thin flowing xylol-balsam on the slide. In this the preparation is 
placed and carefully smoothed down with a brush, and any air-bubbles 
removed with a needle and blotting-paper. The surface of the section 
is then covered with balsam, after which the cover-glass is put on. The 
preparation must now be placed on a perfectly flat surface and allowed 
to dry in this position. When dry the excess of balsam on the slide 
may be easily removed with a knife or with some solvent. 
For lecture purposes the foregoing method gives very satisfactory 
results as the outlines of the tissues and cells are quite clear, and easily 
made out with a hand-lens or low powers. 
Balsam-paraffin for Cells.f — Dr. A. A. Julien observes that the 
mixture of balsam and paraffin for making cells deserves to be better 
known. Balsam-cement is first prepared by slow evaporation of com- 
mercial Canada balsam in a shallow tin pan over a low flame until the 
point is reached of wax-like consistence on cooling, as tested on drops 
removed and cooled from time to time. About a quarter of a pound of 
the hardest commercial paraffin, melting point above 45° C., is heated 
over a low flame to the melting point, a piece of balsam-cement, size of 
a nut, is then added, and the mass digested with frequent stirring for 
about an hour until all the paraffin has a slight yellowish tinge. The 
stock is preserved in a shallow porcelain capsule, so that when required 
it can be readily warmed up. A cell made with this paraffin-balsam is 
ready for use directly after it is spun. 
Apparatus for Holding Cover-glasses.j; — Dr. Veranus A. Moore 
writes as follows : — “ When sections of animal tissue are fastened to 
cover-glasses § in order to transfer them from one bath to another during 
* Bot. Centralbl., liv. (1893) pp. 1-4. 
f Journ. New York Micr. Soc., ix. (1893) pp. 39-43. 
X Proc. Amer. Soc. Micr., xiii. (1892) pp. 51-3. 
§ “ In fastening sections to cover-glasses care must be exercised in the choice of 
some method of fixation which will not leave a film on the cover that will be tinted 
to any degree by the stain used. I have had some trouble in this respect with the 
gelatin, albumen, and collodion processes when certain anilin dyes were subse- 
quently employed. 
A method which seems admirably adapted to this process of handling sections is 
the 'paraffin- alcohol method described by Dr. A. Canini in the Archiv f. Anat. u. 
Phys., Phys. Abth., 1883, p. 147. It consists simply in placing the section on a 
cover- glass directly from the section knife and adding a few drops of dilute alcohol 
