160 Modern Microscopy 



nitric acid, 1 part of acid to 2 parts water. Wash again 

 in water, and stain again in a solution of methyl blue — 100 

 parts of distilled water to 20 parts of a saturated solution 

 of methylated blue — in alcohol for about twenty minutes. 

 Wash in water, and in the case of sections dehydrate in 

 absolute alcohol, clear in oil of cedar or bergamot, and 

 mount in balsam. The cover-glass preparations must be 

 dried ; then add a drop or two of balsam, and mount as 

 above. 



Ziehl Neelsen's Method. — Fuchsin 1 part, 5 per cent, 

 watery solution of carbolic acid 100 parts, absolute alcohol 

 10 parts. Eemove the section from the alcohol, and 

 immerse in the above stain for fifteen minutes. 



Decolourize in a 5 per cent, watery solution of sulphuric 

 acid, wash well in water to remove acid, and counter-stain 

 in the following for five minutes : Saturated alcoholic solu- 

 tion of methyl blue 1 c.c, distilled water 5 c.c. Wash in 

 water, dehydrate in absolute alcohol, clear in cedar-oil, and 

 mount in Canada balsam. 



Gibbe's Double Stain. — Eose aniline hydrochloride, 

 2 grammes ; methyl blue, 1 gramme ; rub well together in a 

 mortar. Then dissolve aniline oil 3 c.c. in 15 c.c. of rectified 

 spirit, and add the crystals to tbe mixture ; shake well, and 

 when all are dissolved, add 15 c.c. of distilled water. Place 

 the cover-glass preparation or sections in the stain in a 

 watch-glass, and warm gently over a spirit-lamp ; then let 

 them soak for four or five minutes. Wash in methylated 

 spirit until no colour will come away, clear in oil of cedar, 

 and mount in Canada balsam. 



Cover-glass preparations will not require clearing ; they 

 are allowed to dry, then add a drop of balsam and mount 

 on a slide. 



Anthrax Bacillus. 



Lbffler's Alkaline Blue Method. — To 100 parts of a 

 solution of caustic potash (1 in 10,000) in distilled water, 

 add 30 parts of a saturated alcoholic solution of methylene 



