MICROSCOPICAL TECHNIQUE. 213 



mixture of equal volumes of glycerin and water was found to give 

 the best result. As soon as the desired degree of decolorisation 

 is attained, the preparation is washed in water, dried in the air, 

 and mounted in balsam, styrax, or dammar. 



The grana or microsomes were best brought out by staining 

 with some anilin dye and then differentiating with 2 per cent, 

 acetic acid. 



Spores are very easily stained by treating the preparation with 

 boiling phenol-fuchsin and then washing out in 4 per cent, sul- 

 phuric acid. 



The yeasts used for these observations were natural cultiva- 

 tions of ordinary bottom yeasts. The yeast was shaken up with 

 distilled water, and then, after settling, the fluid decanted off. 

 The sediment, after having been thus treated several times, was 

 kept for observations. 



Minute Structure of Butter."^— J. Ferdinand points out that, 

 when microscopically examined, the fat-cells of pure butter 

 appear round and regular. Granular masses of casein and albu- 

 minous matters may be seen in addition if the butter has not been 

 prepared carefully, and occasionally spores or filaments of penicil- 

 lium are present under these circumstances. Added animal fat (as 

 in margarine) shows crystals, either separate or in groups. The 

 polariscope and selenite plate are of use in examining these. 



Aniline Dyes as Antiseptics.t— Dr. C. Prioux points out that 

 solutions of pyoktanin and gentian violet in the strength of i : 100 

 prevent the development of micro-organisms. Weaker solutions 

 (i : 500 and even i : 2000) arrest the cultures of the typhoid 

 bacillus and B. coli communis. One per cent, solutions of safra- 

 nin hinder the development of Eberth's bacillus, and it is main- 

 tained that the violet anilines constitute the most powerful 

 antiseptics. 



Glycerine Jelly for Mounting.^— The difficulty of satisfactorily 

 enclosing micro-mounts prepared with pure glycerine has induced 



* Journal d^ Hygienic. 



\ Merck'' s Bulletin. 



X PharviacetUical Journal. 



