ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 115 



1 p.c. watery solution of ammoiiiuin carbonate. This last substance is 

 a better mordant than phenol or anilin-water, and by ttis method 

 more tubercle bacilli can be demonstrated than by the other methods 

 described. Bacilli, which appear only in degenerate granular form in a 

 Much preparation, are clearly seen in films stained in the way described. 



Rapid Method of Staining Spirochastes.* — Tohl Shmamine fixe& 

 the smear on a cover-glass with heat or with methyl-alcohol. Three or 

 four drops of 1 p.c. caustic potash are then added, after which some 

 drops of ordinary aqueous fachsin or of saturated aqueous crystal-violet 

 solution are at once poured on. After about 3 minutes the preparation 

 is washed with water, dried and mounted in balsam. Instead of potash, 

 4-5 p.c. solution of sodium carbonate oi strong ammonia may be used. 



Muci-carmin Staining Method. t — P. C. Cole remarks that this 

 method attracted little attention until S. Handley used it for tracing the 

 spread of carcinoma in the large bowel. The stain is prepared by 

 mixing carmin 1 grm., aluminium chloride 0*5 grm., and distilled water 



2 c.cm. These ingredients are heated in a flat dish over a sand bath 

 until the steam acquires a pungent odour. Alcohol (50 p.c.) is then 

 stirred in and the mixture is transferred to a stock vessel and diluted 

 with 50 p.c. alcohol up to 100 c.cm. So prepared, the solution stains in 

 about 10 minutes ; it is better, however, to use it much diluted. In 

 sections the nuclei should be first stained, e.g. by means of Ehrlich's 

 hematoxylin. After 10 minutes or so in the muci-carmin, this stain is 

 washed off in distilled water and may then be mounted in the usual way. 

 The material is best fixed in formalin or in acetic-sublimate. 



Arnold, J. — Staining of Glycogen in Gastric and Intestinal Mucosa. 



Arch. Mikrosk. Anat., Ixxvii. (1911) pp. 346-76 (1 pi.)- 



(5) Mounting-, including- Slides, Preservative Fluids, etc. 



Mounting. I — It is often desirable, says R. 0. S., to prevent the 

 cover-glass from sinking and crushing the specimens (perhaps delicate 

 diatoms mounted on the slip). To do this I suggest the use of glass 

 threads, which have advantages over the metal discs used by some 

 diatom mounters, for they cannot oxidize and discolour the mounting 

 medium, and, moreover, are easily prepared of almost any required thick- 

 ness. They can be made as follows : Take a piece of ordinary glass- 

 tubing about the thickness of a pencil or less, and, holding it with both 

 hands, bring it gradually down over a spirit or Bunsen flame, at the 

 same time twisting it with the fingers so that the glass may be equally 

 heated all round. Heat the portion of the glass between the hands, 

 but do not heat too large an area if a fine thread is wanted. When the 

 glass has become thoroughly softened, remove it quickly from the flame 

 and instantly give a quick but steady pull with both hands. The 

 heated portion will then be drawn into a very fine thread, 3 ft. or 4 ft. 

 in length. The glass must be removed from the flame before it is 



* Centralbl. Bakt., Ite Abt. Orig., Isi. (1911) pp. 410-11. 

 t Proc. Roy. Soc. Med., Path. Sect., v. (1911) pp. 33-5. 

 t English Mechanic, xciv. (1911) pp. 326-7. 



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