224 CHARLES SLATER. 
was quite certainly stained in five minutes in cold diluted alco- 
holic solutions of rubin, fuchsine, and magenta, prepared accord- 
ing to Baumgarten’s directions. The preparations were de- 
colourised by acid alcohol (v. supra) and counterstained with 
methylene blue. Cold concentrated aqueous solutions of these 
two dyes also stained tubercle bacilli perfectly well, and they 
resisted the same subsequent treatment as when stained by the 
dilute alcoholic solutions. 
The cover-glasses spread with the sputum from the 
leper gave similar results. There was, however, in these 
specimens a decidedly greater tendency for many of the bacilli 
to have their red stain partially replaced by the methylene blue, 
which, supposing them to be leprosy bacilli, a¢cords with what 
is subsequently noticed as to the behaviour of undoubted 
leprosy bacilli in sections. 
The sections were trausferred to the stains either direct 
from absolute alcohol or from water. Those transferred from 
alcohol stained rather the more strongly, but the results were 
not substantially modified. 
It was found that in sections both the Bacillus lepre 
and B. tuberculosis were stained unmistakably by both 
Baumgarten’s methods. 
They were also both stained in six minutes in cold concen- 
trated watery solutions of rubin or magenta, with subsequent 
treatment by acid alcohol. It was not possible to confirm 
this last result in the case of human tuberculosis. 
It is obvious, then, that there is no essential microchemical 
difference in the behaviour of the two bacilli. 
It is of interest to observe that in the two sets of sections 
similarly stained, though the leprosy specimens showed a far 
greater number of bacilli, yet on the whole the tubercle bacilli 
were the clearer and took a purer stain. There was a strong 
tendency for the leprosy bacilli to be purplish in colour— 
partially stained by the methylene blue. It was noticeable, 
too, that the general appearance of the section seen with a low 
power was quite different in these rapidly stained specimens 
from that presented by more fully stained sections. In these 
