156 Mr. F. W. Twort. Method for Isolating and [Sept. 30, 
[Note added October 20th, 1910.—Dr. Sidebotham, of the Public Health 
Laboratory, Manchester, has kindly identified the chromogenic organism 
worked with in the above experiments. He describes it as follows :— 
Bacillus, non-motile, no cilia; size, 2x05; often in pairs, no chains. 
Grows best at 22° C.; growth ceases at 30° C.; grain negative. 
A. P. B—Greenish yellow ; smooth growth. 
G. P. B—Growth all round stab; growth spreads on surface; central 
raised pale yellow projection, surrounded by pale pink smooth area; gelatine 
very slowly liquefied. 
Potato.—Very bright lemon-yellow; irregular knobby growth. 
Milk.—Colour, brown to pale brown ; no acid change. 
The characteristics seem to be similar to those of B. Helvolus 
(Zimmermann). ) 
The above characteristics have also been observed by one of us (G. J. F.) 
in the case of an organism regularly occurring in an experimental filter 
dealing with liquids containing phenolic compounds. | 
A Method for Isolating and Growing the Lepra Bacillus of 
Man. (Preliminary Note.) 
By. W. Dwort. 
(Communicated by Leonard Hill, F.R.S. Received September 30,—Read 
November 17, 1910.) 
(From the Laboratories of the Brown Institution, University of London.) 
For a number of years different investigators have attempted to cultivate 
the lepra bacillus of man and the allied organisms found in the rat and 
other animals. It is not intended in this preliminary note to discuss the 
numerous papers which have been published from time to time from the 
various English, Continental, and American laboratories. These papers 
deal with non acid-fast bacilli, or with acid-fast’ bacilli growing quickly on 
ordinary media, which, in the opinion of the writer, are contaminating 
organisms, and not the true lepra bacillus. So far, no one has produced a 
culture of acid-fast bacilli isolated from a leper, and showing the characters 
of the lepra bacillus as found in the tissues of man. It was with the 
object of obtaining a pure living culture of the lepra bacillus that these 
investigations were undertaken. 
