Prof. Baumgarten has just published in the _Ctbl. f. d. Med. Wiss_., 25,
1882, the following easy method to detect in the expectorated matter of
phthisical persons the pathogenic tubercle bacilli:
Phthisical sputa are dried and made moist with very much diluted potash
lye (1 to 2 drops of a 33 per cent. potash lye in a watch glass of
distilled water). The tubercle bacilli are then easily recognized with a
magnifying power of 400 to 500. By light pressure upon the cover glass
the bacilli are easily pressed out of the masses of detritus and
secretion. To prevent, however, the possibility of mistaking the
tubercle bacilli for other septic bacteria, or vice versa, the following
procedure is necessary: After the examination just mentioned, the cover
glass is lifted up and the little fluid sticking to its under side
allowed to dry, which is done within one or two minutes. Now the cover
glass is drawn two or three times rapidly through a gas flame; one
drop of a diluted (but not too light) common watery aniline solution
(splendid for this purpose is the watery extract of a common aniline ink
paper) is placed upon the glass. When now brought under the microscope,
all the septic bacteria appear colored intensely blue, while the
tubercle bacilli are absolutely colorless, and can be seen as clearly as
in the pure potash lye. We may add, however, that Klebs considers his
own method preferable.
As the whole procedure does not take longer than ten minutes, it is to
be recommended in general practice. The consequences of Koch's important
discovery become daily more apparent, and their application more
practicable.
* * * * *
[Concluded from SUPPLEMENT No. 384, page 6132.]