38 Proceedings of the Royal Physical Socvety. 
daily under the microscope. The result was that the bacilli 
underwent retrogressive changes very rapidly—in fact, after 
the third day I could obtain no traces of the original bacilli. 
It seems evident, therefore, that ‘25 per cent. of carbolic 
acid is much too high, as the bacilli are speedily killed by it, 
at least in very weak solutions of Liebig’s extract. The bacilli 
are not, however, so readily killed in milk diluted with its 
own volume of water, and to which carbolic acid is added 
till it amounts to ‘25 per cent. of the whole mixture. The 
reason probably is, that some of the free carbolic acid com- 
bines with the proteids of the milk, and the antiseptic action 
of the acid is thereby considerably diminished. 
CARBOLISED BrotH (3rd day). 
Protoplasm of Bacilli aggregated 
into sphere-like masses. CARBOLISED MILK (3rd day). 
Bacilli elongated into filaments. Protoplasm 
broken up into spheres at one end of each 
filament. 
2. The high temperature method of isolating the bacillus 
of typhoid fever was introduced by Rodet? about two years 
ago. He recommended a temperature of 44° to 44°5 C., but 
he admitted that the bacillus coli communis (a feecal organism) 
could withstand a higher temperature (46°°5) and yet grow 
well when inoculated into gelatine and “plated.” In a 
somewhat later article Rodet and Roux? maintain that 
Eberth’s, or the true typhoid, bacillus is nothing more nor less 
than the bacillus coli communis in a state of attenuation or 
degeneration. 
Before passing on to the third method of isolating the 
typhoid bacillus from other micro-organisms, I should like to 
call your attention to Dr Vincent’s method,’ which appears 
to be a combination, with modification, of the first and second 
1 Comptes Rendus de la Soc. de Biologie, 1889, and No. 8, 1890. 
+ fod., No. 7, 1890, 3 Tbid:, No. 5, 1890. 
