ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 265 



(blue 0*5, azur - 5, water 100) and an aqueous solution of carbonate of 

 soda 0*5 p.c., is incubated at 37° or more for 24-48 hours. To this is 

 added an aqueous solution of eosin, the strength of which varies with the 

 quality of the blue. The exact quantity must be determined by trying, e.g. 

 • 1, " 25, • 3 p.c. From the filtered mixture is obtained a powder soluble 

 in water and absolute alcohol. The method of staining is as follows : — 

 0*04 grm. of the blue prepared as given above is dissolved in 20 c.cm. 

 methylic alcohol and 0*05 grm. eosin in 1000 of water. On an 18 mm. 

 cover-glass is placed some protozoal blood. To this are added 4 drops 

 of the blue solution. After exactly 3 minutes, and without washing, 

 8-10 drops of the eosin solution are poured on and allowed to act for 

 2 minutes. 



If the coverslips be larger, a proportionately larger quantity of the 

 staining solutions must be used, and, of course, slides may be used 

 instead of slips. 



The preparations are merely washed in water, dried, and mounted in 

 balsam. 



While the staining is going on, the preparations must be covered to 

 avoid evaporation and precipitation. 



For staining films of microbes fixed in the flame, a 1 : 500 aqueous 

 solution of the blue is allowed to act for half to one minute. 



Differential Staining of Bacillus Typhosus in Sections.* — Bonhoff 

 recommends the following method. The section, taken out of absolute 

 alcohol, is washed and fixed on the slide ; it is then treated cold for 

 two minutes, with 5 drops of a freshly prepared mixture of saturated 

 alcoholic methylen-blue (4 drops), Ziehl's solution (15 drops) and dis- 

 tilled water (20 c.cm.) ; it is now warmed over a small gas jet until 

 it commences to steam, washed in water, then in 1 p.c. acetic acid, and 

 again in water ; dried with blotting paper, and washed with several lots 

 of anilin and xylol equal parts, ancl mounted in balsam. The section is 

 stained throughout a light red, the bacilli having an intense sky-blue 

 colour. 



Christian, H. A.— Newer aspects of the Pathology of Fat and Fatty Degeneration. 

 [Mentions use of Osmium tetraoxide, Sudan iiL,_Scharlach R., and Indophenol 

 for staining fat, and the technique required.] 



Johns Hopkins Hosp. Bull., xvi. (1905) pp. 1-6. 



Metallography, etc. 



Sulphides and Silicates of Manganese in Steel.t — J. E. Stead 

 points out that the identity in shape of the globular masses of these 

 substances may have caused them to be confused with one another. He 

 found that, if the polished surface of a section were examined previously to 

 etching, particles of a pale dove-colour could be tentatively accepted as 

 sulphide. In the case of very minute particles, the reflected actinic 

 light from sulphide of manganese is greater than that from the silicate, 



* Centralbl. Bakt., l te Abt. Ref., xxxv. (1905) p. 794. 

 t Iron and Steel Mag., ix. (1905) pp. 105-13 (4 figs.). 



April 10th, 1905 ■ t 



