ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 499 



rub to and fro with the ball of the finger until the papillae are distinctly 

 visible. Then after drying and cleaning by rubbing between the fingers, 

 mount in balsam. Put some very thick balsam on the centre of the 

 slide, and also on the cover-slip, then place the section on the slide and 

 press the slip firmly down. 



Improved Method of Sectioning" Carbonised Wood.* — L. Wittmack 

 and J. Buchwald saturated the material with Canada balsam or with 

 paraffin, and then made sections of the prepared mass. Some of the 

 sections were incinerated on platinum foil and the ash transferred to 

 xylol or balsam. Their best results were obtained by first incinerating 

 the wood and then working up the ash into microscopical sections. A 

 piece of carbonised wood of suitable size was incinerated, and the residue 

 amalgamated with hot liquid paraffin. The blocks thus obtained were 

 sectioned. The sections, after having been straightened on the slide, 

 were treated with xylol and mounted in balsam. 



(4) Staining' and Injecting. 



Influence of High Temperatures on the Stainability of Bacteria.f 

 — G. Gabritschewsky records some interesting observations on the be- 

 haviour of bacterial films to staining solutions at different high tem- 

 peratures. The first series relates to acid-fast bacteria. After staining 

 for 5 minutes with carbol fuchsin, these bacteria, B. tuberculosis Iwminis, 

 avium, piscium, B. moller it. (grass), B. horn (butter), B. marpmann 

 (urine), were decolorised by 5 p.c. sulphuric acid if the preparations 

 had been previously heated to 180° C. They still retained the Gram 

 staining, but lost it at lUO , though up to 200° they would stain by 

 simple solutions. In the second series were B. anthracis, B. subtilis y 

 and B. pseudo-anthracis. Up to 160° B. anthracis with spores stained 

 well witb carbol-fuchsin. By Gram's method both bacilli and spores 

 stained up to 180°, but at 190° the spores only retained the dye. In the 

 third series cultures of diphtheria and pseudo-diphtheria showed the 

 Ernst-Neisser granules up to 170°. By Gram's method diphtheria 

 bacilli did not stain at 180°, while the pseudo-diphtheria retained it up 

 to 19C°. 



New Method of Staining Neuroglia.:}: — D. Anglade and C. Morel 

 state that the following method gives sharper details, and is more easily 

 managed, than the ordinary procedures. The material is hardened in a 

 mixture composed of Fol's fluid 3 parts, and sublimate solution 7 p.c. 

 1 part. The preparations are placed in an autoclave at 37° for 45 hours. 

 On removal they are washed, and then dehydrated in alcohol. After satu- 

 rating in aceton (24 hours) the material is imbedded in paraffin (3 hours). 

 The sections are stained in warm saturated aqueous solution of Griibler's 

 Victoria-blue and heated until it vaporises. They are next treated with 

 Gram's solution, and afterwards with a mixture of xylol 1 part, anilin 

 oil 2 parts, after which they are imbedded in balsam, or better still, in 

 amber-lac. 



* Ber. Deutseh. Bot. Ges., xx. (1902) p. 21. See Zeitschr. wiss. Mikr., xviii. 

 (1902) p. 508. f Centralbl. Bakt., 1" Abt., xxxi. (1902) pp. 813-i. 



% Rev. Neurol., ix. (1901) pp. 157-8. 



