EXTRACTS PEOM FOREIGN JOURNALS. 
451 
EXTRACTS FROM FOREIGN JOURNALS. 
AN EASY METHOD OF DETECTING BACILLUS TUBERCULOSIS FOR 
DIAGNOSTIC PURPOSES. 
By George Piersal, M.D. 
* * * There is at the present time probably no other sub¬ 
ject receiving an equal amount of earnest study and careful in¬ 
vestigation with that of the discoveries of Koch, regarding the 
bacillus of tubercle. While these researches bid fair to yield the 
most important results, it is no disparagement to that excellent 
observer to assert that extended investigations into the modifica¬ 
tions naturally resulting from the manipulations of other laborers 
in the same field will alone develope and complete our knowledge 
of the conditions of existence and life-history of micro-organisms, 
and determine the exact significance 7 of their presence or absence, 
from a practical stand-point. 
It will be remembered that the demonstration of the presence 
of this bacillus, as well as its chief distinctive feature, depends 
upon its appropriation of certain coloring matters, while the or¬ 
dinary bacilli of putrefactive change remain unaffected. The 
method heretofore employed by Koch has been very unsatisfac¬ 
tory from the fact of its uncertainty and frequently entire failure. 
The modifications suggested by Ehrlich yield more uniform re¬ 
sults, without, however, overcoming the element of uncertainty. 
Dr. ITeneage Gibbs, in the Lancet , has recently given his plan of 
staining the bacterium, claiming for the method both uniformity 
and certainty of action. 
The coloring matters employed are magenta crystals and 
chrysodin (chrysoidin). The latter is a brown, staining the 
ground-substance, but with less intensity than vesuvin. There 
solutions are required: 
(a.) Magenta crystals, 2 grams; pure aniline, 3 grains; alco¬ 
hol (s. g. 830) 20 c. c.; distilled water, 20 c. c. Dissolve the 
analine colors in the alcohol, rubbing them up in a glass mortar, 
adding the spirit gradually until all the color is dissolved, then 
add water slowly while stirring. Keep in a stoppered bottle. 
( b .) Saturated solution of chrysoidin in distilled water; add 
a crystal of thymol to prevent deterioration. 
(c.) Dilute solution of nitric acid, one part, and two of distilled 
water. 
