46 
THOMPSON YATES LABORATORIES REPORT 
Morphology 
In i p.c. the bacilli have much the same appearance as in ordinary broth, 
but the size decreases with the increase in the amount of glucose. 
Bacillus Coli Communis 
Motility 
A fairly motile B. c. c. was used, and it was found that motility decreased 
with an increased percentage, until in 4 p.c. it was doubtful whether the 
bacilli were motile. 
Morphology 
The bacilli become shorter as the percentage rises. 
B. Enteritidis of G^ertner 
The effect of glucose upon this organism is the same as upon B. t. a. 
and B. c. c. 
[All the experiments up to this point were carried out in the Bacteriological 
Laboratory at Guy's Hospital during the winter of 1897 and the first half of 1898. 
Then an interruption occurred and they were not resumed until 1900, in the 
Thompson Yates Laboratories, University College, Liverpool.] 
The conclusion arrived at from the first series of experiments was, that by 
using a liquid bile salt medium, an incubation temperature of 42° C, and subsequently 
plating in ordinary nutrient gelatine, one could inhibit the growth of most of the 
organisms usually found in faeces. The thought naturally arose that possibly some of 
the organisms isolated were merely existing in the bile salt medium without 
multiplication, and that it was the subsequent plating in a more favourable medium 
that enabled them to grow. Therefore an agar medium was tried ; at first without 
peptone, but later, when it was seen that peptone did not increase the number of species, 
a slightly alkaline agar, composed as follows, was used : — 
Bile salt . . . .1 gramme. 
Peptone .... 0.2 „ 
KNO3 • . .0.5 „ 
Na,HP0 4 . . .0.5 „ 
AmCl . . . . 0.5 „ 
Agar . . . . 2 „ 
Tap water . . .100 c.c. 
When used for sewage effluents this medium gave an almost pure culture of 
the B. c. c. group ; but when used for pure cultures of B. c. c, and compared with 
nutrient agar, the bile salt medium frequently inhibited too much. 
The following are examples of the results obtained : — 
I. About two grammes of garden earth were shaken up with about 100 c.c. of 
tap water in a flask, which was then allowed to remain at rest until the larger particles 
