EEMAEKS ON TECHNIQUE 



17 



acid, ten to thirty seconds (or in a 3 per cent, solution of hydrochloric acid in 70 per 

 cent, alcohol, till the section is quite pale). If the section is still red, repeat the 

 decolorization. Wash carefully in water ; then aqueous methylene blue, five 

 minutes ; better (Cornet-Meyer), also in haematoxylin. Wash, clear, and mount. 



(b) BorreVs Method. Embed in celloidin or paraffin. First stain sections 

 in hsematoxylin (complete differentiation) ; then stain in Ziehl-Neelsen's solution 

 cold for twenty-four hours (10 c.cm. sat. ale. fuchsin sol. +100 c.cm. 5 percent, 

 carbolic ac. in distilled water) ; wash with water ; put in 20 per cent, aqueous 

 aniline hydrochloride for twenty to thirty seconds. Differentiate in 96 per cent, 

 alcohol, carbol xylol, balsam. 



Sublimate is best for fixation, especially if (Borrel) 5 per cent. ac. acet. glac. be 

 added. Zenker's solution is also very good. Formol is objectionable, as after its use 

 the tissues are strongly fuchsinophile. Alcohol fixation, too, is less suitable. 



Lepra Bacillus Staining in Sections (Baumgarten). 



Dilute alcoholic solution of fuchsin (1 : 4) six to seven minutes ; differentiate with 

 10 per cent, nitric acid in alcohol ; wash with water ; counter -stain with methylene 

 blue twenty to thirty seconds. 



Lepra bacilli, in contrast to tubercle bacilli, stain very rapidly, even with this 

 dilute solution. 



Neisser's Granule Staining (Babes-Ernst Bodies in Bacilli of the Diphtheria 

 Group). 



(a) Acetic methylene blue (cone. ale. methylene blue, 20 ; aq. dist., 950 ; ac. acet. 

 glac., 50) ; stain for one to three seconds. 



(6) Wash with water. 



(c) Contrast stain with Bismarck brown (Bismarck brown, 2 ; boiling distilled 

 water, 1,000 ; filter) for three to five seconds. 1 Bacilli appear light brown, and the 

 granules dark blue (cf. Fig. 4). 



Neisser, in his latest paper, recommends : 



Solution a. 

 Methylene blue powder 



Alcohol 



Aq. dist. 



Ac. acet. glac. 



Parts. 

 1 



20 



1,000 

 50 



Solution b. 

 Crystal violet (Hochst) 

 Alcohol ... 

 Aq. dist. 



Parts. 

 1 



10 



300 



Mix 2 parts of Solution b with 1 part of Solution a, stain for one second, 

 immediately wash with water, and stain with chrysoidin (1 : 300 hot water and 

 filter) for three seconds, wash, and dry. 



Scheller (Zentralblatt f. Bakt., 1905, xxxviii., Ref., p. 6) recommends ten to fifteen 

 seconds for each dye. 



For the diagnostic value of this stain, see chapter on ' Diphtheria,' p. 193. 



Roux's Stain for the Diphtheria Group. (1) Dahlia violet, 1 ; alcohol 90 per 

 cent., 10; aq. dist. to 100. (2) Methyl green, 1; alcohol 90 per cent., 10; aq. dist. 

 to 100. Mix 1 part of (1) with 3 parts of (2), and stain in the mixture for two 

 minutes without heat. Bacilli are red, granules violet. 



Stains for Spirochaeta pallida (Schaudinn). 



The thinnest possible films of the tissue are made on slides or cover-glasses, and 

 fixed in alcohol for fifteen minutes, or exposed to osmium vapour for a few seconds 

 (Schaudinn). 



1 Czaplewski recommends eight to ten seconds. 



2 



