ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
477 
when tubercle bacilli are very scanty in the sputum. Some of the 
sputum is to be shaken up with water and some of the sediment spread 
on a slide, and if there be any small but thickish particles of mucus on 
the slide the layer is to be squeezed into a film by means of another slide 
placed thereon. The slides are best dried on an asbestos plate heated in 
the flame. When fixed, carbol-fuchsin is poured on the film and allowed 
to act for 8-10 minutes. The solution is composed of fuchsin, 1*0; 
alcohol, 20 ; acid, carbol., 5; distilled water, 100. After having been 
washed with water the preparation is treated for five minutes with the 
following acid solution: — Acid. mur. pur., 10 drops; distilled water, 
20 ccm. ; 90 per cent, alcohol, 100 ccm. The slide is again washed, and 
if not sufficiently decolorised the acid solution must be repeated. If 
sufficiently decolorised the preparation is contrast-stained with malachite 
solution, washed again with water and alcohol, and then dried. 
C3) Cutting-, including- Imbedding- and Microtomes. 
Apparatus for Preserving Celloidin-Blocks on the Microtome.* — 
Herr G. Alexander describes an apparatus which he has found useful for 
preserving celloidin-blocks, especially when intended for cutting serial 
sections. It consists of a quadrangular block with a circular top. The 
square portion is fixed by the microtome-screw. The circular top has 
an inbevelled edge, to which a glass tube can be adapted. The tube is 
3 • 5 cm. high, and has a cover or lid. If it be necessary at any time to 
suspend operations, the cylinder is put on and the junction with the 
bevelled edge filled up with vaselin. A jar is thus formed, at the bottom 
of which lies the celloidin-block. Spirit is poured in and the cover put 
on. By this means a celloidin-block is kept not only unimpaired but in 
the proper position for sectioning at some future occasion. 
New Methods for Paraffin Sections.! — Dr. H. Albrecht and Dr. O. 
Stoerk fix paraffin sections to the slide in the following way. The 
section is placed on an un warmed slide on some water and then stretched 
by simply breathing on it. It is then pressed on the slide with blotting 
paper and fixed firmly by pouring on a couple of drops of very thin 
celloidin solution. This method is said to be very successful, and quite 
avoids any crumpling of the section and also loss of time. For tissues 
fixed with osmic acid, however, the foregoing procedure and the albumen- 
glycerin method are combined. In this the water drop is placed on the 
albumen-glycerin layer; the section is then breathed on and pressed 
down on the slide with filter-paper moistened with a few drops of 
absolute alcohol. The following rapid method, which avoids crumpling, 
is also given. The pieces throughout the procedure are kept at a tem- 
perature of 55°, and first come into 95 per cent, alcohol. The thickness 
should not exceed 1 cm. After an hour, a piece 1/2 cm. thick is cut off 
and transferred to absolute alcohol. In another hour it is put into 
absolute alcohol for two hours, and then for three hours into alcohol 
kept water-free by means of copper sulphate. It is next transferred to 
xylol-paraffin, where it remains for three hours. Finally, it passes into 
paraffin with melting-point of about 52° for one hour. 
* Zeitschr. f. wiss. Mikr., xiii. (1896) pp. 10-12 (2 figs.). 
t Tom. cit., pp. 12-18. 
