1910. | Growing the Lepra Bacillus of Man. 157 
The material used was the nasal discharge and scrapings from a typical 
leper. The discharge showed large masses of lepra bacilli and a number 
of contaminating micro-organisms. Firstly, most of the contaminations 
were killed by placing the discharge in a 2-per-cent. solution of ericolin 
at 38° C. for one hour as recommended for the isolation of the tubercle 
bacillus* ; then cultures were made from the sediment on to different media. 
and incubated at 38° C.t 
All the ordinary laboratory media, including Dorset’s egg medium, gave 
negative results. A number of special media containing extracts of fresh 
gland and other tissues were tested next, the extracts being freed from 
any contaminating micro-organisms by passing them through a Doulton 
white filter; these also gave negative results. 
In view of the close relationship between the tubercle bacillus and the 
lepra bacillus, it appeared highly probable that these two organisms would 
require the same chemical substances for building up their protoplasm, which 
could be elaborated from the ordinary media only by the tubercle bacillus. It 
was thought that if these substances could be supplied, already formed, to the 
lepra bacillus, it might grow, and the easiest method of supplying these 
substances would be by adding to some good medium the ground-up bodies of 
tubercle bacilli containing them. Accordingly, a number of tubercle cultures 
were taken and inoculated on to Dorset’s egg medium; when sufficiently 
grown the tubes were steamed and the growth of tubercle scraped off 
the surface, care being taken to avoid the medium containing the waste 
products of the tubercle growth. The tubercle bacilli so obtained were 
ground up with glycerine and saline, steamed for half an hour and added to 
the yolk and white of new laid eggs in the following proportions :— 
Eggs, 75 parts; 8 per cent. sodium chloride, 25 parts; mix well and add 
tubercle bacilli, 1 per cent.; and glycerine, 5 per cent., or less. 
The medium was placed in test tubes, heated to 60° C. for one hour, and 
on the following morning incubated at 38° C. for six hours, and again heated 
in water bath at 60° C. for one hour, and set in slopes at 85° C. 
The ericolinised nasal discharge of a leper was inoculated on to this 
medium, the inoculated tubes being capped with gutta-percha tissue and 
incubated at 38° C. After 24 hours the medium absorbed a quantity of the 
ericolin, so the material was lifted off with a platinum loop and rubbed over 
fresh tubes. The bacilli grew and were sub-cultured in pure growth, the 
bacilli growing in sub-cultures as fairly long thin beaded rods; the bacilli were 
* Twort, ‘Proc. Roy. Soc.,’ B, 1909, vol. 81. 
+ Subsequent experiments have shown that 37° is a better temperature (November 19, 
1910). 
VOL. LXXXIII.—B. N 
