PREPARING AND MOUNTING BACTERIA. 203 
is recognized by dealers in our country. A request for red aniline, 
or either of the above, is responded to by offering the same thing. 
Babes, of France, recommends a saturated aqueous solution, pre- 
pared with heat, of aniline violet 1 B. and an exposure of twenty- 
four hours, or the same with gentian violet. He further also modi- 
fies Ehrlich’s method by making a saturated aqueous solution of 
aniline oil, using,heat. To this is added 5 per cent. of absolute 
alcohol and 5 per cent. of a saturated alcoholic solution of fuchsin, 
or of a very concentrated solution of methyl violet 1 B, Twenty- 
four hours are again allowed for the stain, decolourizing with nitric 
acid and water, one part to four. I have prepared the dye used by 
myself as follows: Into twenty grammes of 85 per cent. alcohol, 
stir three grammes of aniline oil, and add this slowly while stirring 
to two grammes of pulverized crystals of fuchsin, the red aniline of 
the shops. To this solution add while constantly stirring twenty 
grammes of distilled water and bottle without filtering. This stain 
keeps well for some months, but gradually becomes unfit for use 
by the precipitation of granules of colouring matter. Doubtless 
this could be prevented by a little experimentation, thus making it 
possible to keep the dye in stock. In practice I have smeared a 
cover glass with a little sputum, dried and heated it as before 
described, and, having poured a little of the dye into one of a nest 
of porcelain dishes, have therein immersed the cover glass, perhaps 
several of them, put a little glycerine around the edge of the dish, 
and covered with another dish. ‘This is left from two to twenty- 
four or even more hours when the cover glasses are taken out and 
freed from the adhering dye by washing in alcohol, usually by a 
stream from a wash-bottle, then immersed in nitric acid and water, 
one part to four, until all colour perceptible to the eye disappears, or 
usually about one minute. Wash thoroughly in water, and mount 
in water for examination. The special organisms should appear as 
minute ruby-coloured rods, in a white field. If desired, the latter 
is stained blue or green by these anilines in glycerine by one 
minute’s application. If for a permanent preservation, after drying, 
mount by placing a minute drop of pure balsam on the centre of a 
slide, and invert the cover glass upon it. Harden with moderate 
heat. These organisms can be seen by sharp eyes without 
staining, and by becoming familiar with their appearances, one can 
pretty certainly pronounce upon their presence without any pre- 
paration, provided they are numerous in the specimen examined, 
but as they alone hold the stain by the above process, it is not only 
easier to detect them when coloured, but to more certainly know 
them from other kinds of bacteria very commonly found in sputa 
of the healthy, as well as the diseased.—American Society of 
Microscopists. 
