18 
Proceedings of Royal Society of Edinburgh. [sess. 
Abstract of the Results of an Inquiry into the 
Causation of Asiatic Cholera. By Neil Macleod, M.D. 
Edin., and Walter J. Milles, F.R.C.S. Eng. Communicated 
by Dr Woodhead. 
(Read December 17, 1888. ) 
This inquiry was commenced in Shanghai at the end of 1884, 
soon after Koch had published some of his results, and as he was 
then almost the only worker in the bacteriological field of whom it 
could be said that he had not published anything, subsequently 
upset, attention was directed at once to the “ comma bacillus.” 
Slightly alkaline peptonised meat jelly on plates was used for 
purposes of cultivation, this being kept at a temperature of 60° to 
70° Fahr. by means of an ice chest in hot weather. 
The investigators worked independently, but the majority of the 
cases of cholera under observation were investigated by both. 
For determining identity, it was assumed that the same organism 
grown under the same conditions as to medium, temperature, and 
time should have the same macroscopic, and being subjected to the 
same conditions as to stain, treatment in mounting and examining, 
the same microscopic characters. 
The characters of identification laid down by Koch for this 
organism are now accepted by all observers as sufficient, the name 
alone being altered. The “ comma bacillus ” is now regarded as a 
“ spirillum,” but is best known by the former name. The charac- 
ters are — 
1st. It occurs in the characteristic cholera stools, and after death 
in the similar contents of the ileum. 
2nd. It is from one-half to two-thirds the size of the tubercle 
bacillus, somewhat thicker than the latter, and slightly curved. 
Sometimes it occurs in groups so as to form a half circle, an 
S-shaped curve, or a wavy line of varying length. 
3rd. It grows in and liquefies slightly alkaline gelatine, more 
slowly in neutral, scarcely at all in slightly, and not at all in 
markedly acid gelatine. On a gelatine plate cultivation the indi- 
vidual colonies are round, lie in a funnel-shaped cavity; viewed by 
transmitted light and magnified, they look like ground glass, and 
