112 
VETERINARIUS. 
made with aqueous solutions of the different aniline colors— 
methyl-blue, gentian-violet, and fuchsin—but the result is more 
satisfactory with other preparations, such as alkaline coloring solu¬ 
tions, prepared by taking three cubic centimetres of a solution of 
caustic potash, 1 to 10,000 parts of aqua, and adding to it a con¬ 
centrated alcoholic solution of either of the above colors. Solu¬ 
tions of aniline water, gentian-violet or fuchsin, as used for tu¬ 
bercle bacilli, give very fine effects when mixed with the same 
quantity of the above mentioned potash salt, or a one-half per 
cent, solution of liq. ammon. fort. The addition of the alkali to 
all coloring solutions is very valuable in the study of bacteria; 
the coloring takes place more rapidly and intensely, and other or¬ 
ganisms, such as the actinomyces fungi, which color imperfectly 
by the Gramm method, color beautifully with the addition of 
caustic potash. 
The mixture must be made fresh each time, as the potash 
forms a precipitate in a short time with gentian-violet or fuchsin. 
Both the alkali and coloring material ought to be filtered before 
use. Float the covering-glass specimens in the solutions for five 
minutes, take out and dip for a second or two in 1 p. c. acetic acid 
solution, to which add sufficient trapacolin, O.O. ; then wash speci¬ 
mens quickly in distilled water. The addition of trapacolin has 
the effect of removing the color entirely from the plasma of the 
cells, and somewhat from their nuclei, while the bacilli retain their 
color perfectly. This gives the preparations a peculiarly clear ap¬ 
pearance. i 
By treating similar preparations with concentrated aqueous or 
aniline water solutions according to the ordinary methods of color¬ 
ing bacilli, it is impossible to find those of glanders by subject¬ 
ing them to the action of a fuchsin solution for twenty-four 
hours; a few may be discovered. The result is quite different 
when an alkaline solution is used. For instance, when an alka¬ 
line solution of methylen-blue is used, a section or covering-glass 
specimen has only to remain a few minutes in the mixture to 
color; then proceed as above with the combined solution of 
acetic acid and trapacolin, alcohol, and cedar oil; then mount in 
Canada balsam. When an alcoholic solution of gentian-violet or 
