ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 401 



those free in the plasma (extracellular) behave in a way similar to other 

 organisms. 



In fixed preparations a mixture of 20 ccm. of cold saturated aqueous 

 neutralised solution and 100 ccm. of water stain the cocci deep red in a 

 few seconds, while the nuclei of the cells are but faintly coloured, so 

 that the nuclei do not obscure the cocci. 



New Method of Staining G-onococcus.* — Dr. Dreyer gives the fol- 

 lowing method for staining gonococcus. The preparation is stained with 

 Loeffler's methylen-blue in the usual way, and then, having been washed 

 with water, is treated for 4 minutes with 1 per cent, protargol solution. 

 After differentiation the preparation is washed repeatedly, and then con- 

 trast-stained by immersing it for half a minute in dilute carbol-fuchsin 

 (10 drops Ziehl-Neelsen to a watch-glassful of water). The bacteria are 

 blue, the tissue cells and nuclei red. 



Differences in the Staining Reaction of Friedlaender's Bacillus.J 

 — Dr. P. Clairmont found — from histological examination of the liver and 

 kidney of a case wherein Friedlaender's bacillus had been discovered 

 intra vitam in the pus of an abscess — that the bacteria were not de- 

 colorised in sections which had been stained by Gram's method and 

 afterwards treated with alcohol and oil of cloves, while the colour was 

 discharged from culture preparations of the same origin. 



Petit, L. C. — Refraction versus Stain in Microscopy. 



New York Med. Record, LV. (1899), No. 16, p. 851. 



(5) Mounting:, including- Slides, Preservative Fluids, &c. 



Preparing Glycerin- Jelly.J — Glycerin-jelly for mounting micro- 

 scopical objects and also for museum specimens is easily prepared by 

 placing photographic gelatin in a washing apparatus and leaving under 

 a gentle stream until clean. It is then melted by a gentle heat in an 

 equal quantity of glycerin. After this it should be hot-filtered thrice. 

 A thymol crystal will keep it from becoming mouldy. 



(6) Miscellaneous. 



Method for Demonstrating Actinomycotic Appearances in Tubercle.§ 

 — Prof. P. L. Friedrich and Dr. H. Nosske describe actinomycosis-like 

 appearances which they have found in tuberculosis produced experi- 

 mentally by injecting into the arterial circulation suspensions of tubercle 

 bacilli. The appearances depicted in the illustrations are strikingly 

 like those of actinomvcosis, and show a central mass of bacilli sur- 

 rounded by a zone of club-shaped elements arranged radially. These 

 typical appearances were demonstrated by special staining methods, and 

 the sections exhibit a striking contrast to those stained by carbol-fuchsin 

 and the ordinary method. One of these procedures was hematoxylin 

 staining, followed by Gram and eosin. These sections show violet 

 staining of the tissues, the bacilli being blue and the clubs red. A still 



* Monatsber. iib. d. Gesamintleist. a. d. Gebiete d. Krankb. d. Harn., iii. (1898) 

 No. 3. See Zeitscbr. f. wiss. Mikr., xvi. (1899) p. 383. 



f Wiener Klin. Wocbenscbr., 1899, p. 1068. See Centralbl. Bakt. u. Par., 

 1 M Abt., xxvii. (1900) pp. 272-3. J Journ. App. Microscopy, ii. (1899), p. 641. 



§ Beitrage z. Pathol. Anat. u. z. allgem. Pathol., xxvi. (1899) pp. 470-510 (1 pi. 

 and 4 figs.). 



June 20th. 1900 2 E 



