BACTERIA-STAINING                     135
zLd   171. Rosanilin and Methyl-Blue for Tubercle-Bacteria
 (Heneage Gibbes's method').-Take of rosanilin hydrochloride
t   2 grammes, methyl-blue 1 gramme; rub them up in a glass
I   mortar. Then dissolve anilin oil 3 c.c. in rectified spirit 15
c.c.; add the spirit slowly to the stains until all is dissolved,
"then slowly add distilled water 15 c.c; keep in a stoppered
bottle.
The sputum having been dried on a cover-glass in the
usual manner, a few drops of the stain are poured into a test-
i tube and warmed. As soon as steam rises, pour into a watch-
glass, and place the cover-glass on the stain. Allow it to
remain for four or five minutes, then wash in methylated
is.  spirit until no more colour comes away; drain thoroughly
q   and dry, either in the air, or over a spirit lamp; mount in
balsam.
4, The stain can be used cold equally well, but in that case
the cover-glass must be left on it for at least half an hour.
Ih    The bacilli of tubercle are stained red, micrococci and
I bacteria blue. The results are " very satisfactory, and the
2   horrible nuisance of the nitric acid is avoided."
171a. Gentian-Violet and Iodine, for Schizomycetes in
h Tissues (Gram's method2).-A solution of gentian-violet is
prepared according to the formula of Ehrlich (supra, 167),
r   and the sections, after having been soaked in absolute alcohol,
8   are stained in it from one to three minutes (except in the case
M   of tubercular bacilli, which require twelve to twenty-four
hours). They are then placed in a solution composed of
iodine 1 gramme, iodide of potassium 2 grammes, water 300
c.c. After three minutes therein they are brought into
absolute alcohol (in some cases it is better to immerse them
in absolute alcohol before the iodine bath, as well as after it).
,  ' Lancet,' i (1883), p. 771. ' Journ. Roy. Mic. Soc.' (N.S.), iii (1883),
p. 764.
2 'Fortschr. d. Medicin,' ii (1884), No. 6. ' British Med. Journ.,'
Sept. 6, 1884, p. 486. ' Journ. Roy. Mic. Soc.' (N.S.), iv (1884), p. 817.

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