SYSTEMATIC AND DESCRIPTIVE. 279 



Balmer - Frantzel method. Dissolve two grammes of 

 freshly-powdered gentian-violet in 100 grammes of aniline- 

 water. Immerse the sections for twenty-four hours, and 

 treat as in Ehrlich's method. 



Ziehl's method. Stain with Ehrlich's method, but omit 

 the nitric acid ; after-stain with methylene-blue. The 

 latter replaces the stain of all bacteria except the tubercle 

 bacillus. 



LichtJieims method. Concentrated solution of fuchsine 

 or gentian-violet is diluted with distilled water, and the 

 sections stained for thirty-six hours. 



Peters method. Sections are stained for half an hour in 

 fresh aniline-gentian-violet solution. Transfer to 20 ccm. 

 of absolute alcohol for eighteen hours, the alcohol being 

 renewed two or three times. Rinse in distilled water for 

 one minute, and immerse for three minutes in a watery 

 solution of aniline-yellow (aniline-yellow *2 dissolved in 

 distilled water 10, filter). Wash in absolute alcohol, clarify 

 with clove-oil, and preserve in Canada balsam. 



Franker s method. Sputum preparations are rapidly 

 double-stained by the following method : Prepare a solu- 

 tion by adding concentrated alcoholic methyl-violet or 

 fuchsine solution, drop by drop till opalescence arises, to 

 5 ccm. of aniline-water heated to 1 00 C. Float the 

 prepared cover-glasses two minutes in the warmed solu- 

 tion. The process of after-staining and decolorisation is 

 effected by placing the preparation for one to two minutes 

 in one of the following solutions : for fuchsine-stained 

 preparations a saturated solution of methylene-blue in a 

 mixture of 



Alcohol 50 



Distilled water .... 30 

 Nitric acid . , . . . 20 



which is filtered before use ; for preparations stained in 

 methyl-violet, a saturated solution of vesuvin may be used in 



