ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 217 



methylen-blue in the usual way. It is then washed, dried, and mounted. 

 By the foregoing process the most refractory spores are stained. 



New Staming-trough for Serial Sections.*— Dr. H. Hellendall has 

 devised a trough for staining simultaneously a large number of sections 

 (fig. 34). It is made of glass, is 8 cm. long, 3 cm. broad, and 8 cm. high. 

 Along each side are seven ribs or fillets, each being 5 cm. high and 

 0'5cm. thick. These fillets are blown into the vessel, and thus eight 

 open compartments are formed, in each of which a couple of slides placed 

 back to back con be located. 



C5) Mounting-, including- Slides, Preservative Fluids, &c. 



New Fixative Solution, and Method for Restoring Old Specimens.! 

 — Prof. M. Lavdovsky has found the following fixative give especially 

 good results: — 1 p.c. acetic acid 500 ccm. : chemically pure bichromate 

 of potash 20-25 grm. ; saturated aqueous filtered solution of sublimate 

 5-10 ccm. This combination acts well not only with fresh tissues, but also 

 with old material, acting thereon like a restorative. The solution may 

 be used as given, or diluted with an equal quantity of water. Fixation is 

 completed in two or three days, the pieces being afterwards hardened in 

 alcohol for 2-7 days. 



The more important points in the restoration method are as fol- 

 lows. The slide is immersed for 21—18 hours, or longer, in turpentine 

 oil, xylol, or toluol, until the cover-glass is easily separable from the 

 slide. The slides, provided that the sections are not too firmly adherent, 

 are placed in 95 p.c. to 100 p.c. alcohol for 15 minutes, and then in 

 water for 5 minutes. The slides are then immersed for 6-24 hours 

 in the chromaceto-sublimate solution diluted with half its bulk of 

 water. After having been carefully washed with water, the slide is 

 transferred to Weigert's acetic acid-copper solution for 6-24 hours. 

 The preparation is again washed with water, and then placed in 

 Weigert's hfematoxylin solution, diluted with an equal bulk of water, 

 for 6-12 hours, after which it is decolorised in the borax-ferrid- 

 cyanide solution. This must be diluted with one or two volumes of 

 distilled water to prevent too rapid decoloration. When the preparation 

 has been thoroughly washed, it is dehydrated in 95 p.c. alcohol, cleared 

 up in oil of cloves and xylol, and mounted in balsam. The foregoing 

 procedure is suitable for animal and vegetable tissues. 



Formalin as a Wet Method for Blood-Films.} — The method 

 described by the Hon. G. Scott is as follows : — Hold the film, wet side 

 down, in the mouth of a wide bottle half filled with 40 p.c. solution of 

 formic aldehyde for about 5 seconds. Drop, while still wet, film down- 

 wards, into absolute alcohol: leave for 15 minutes to 48 hours. Mop 

 up on blotting-paper, and then before any drying occurs, drop on a few 

 drops qf eosin-methylen-blue stain, cover with a watch-glass, stain for 

 not longer than 2 minutes. Eun off excess of stain, and rinse in dis- 

 tilled water twice. Mop off excess of water. Dehydrate rapidly in 

 absolute alcohol ; then treat with xylol three times rapidly, and mount 

 in balsam. The film must not be allowed to dry at any stage. 



♦ Zeitschr. wiss. Mikr., xvii. (1900) pp. 299-300 (1 fig.). t 'lorn, cit., pp. 301-11. 

 t Joum. Pathol, and Bacterid., vii. (1900) pp. 131-6. 



