156 THOMPSON YATES LABORATORIES REPORT 
77- 
B. diffusus 
78. 
B. fluorescens aureus 
79- 
B. fluorescens mesentericus 
80. 
B. tuscus 
81. 
B. gelber (Korn) 
82. 
M. mycoides 
83- 
B. proteus mirabilis 
84. 
B. proteus Zenkeri 
85. 
B. ramosus 
86. 
B. of haemorrhagic septicaemia 
87. 
M. agilis 
88. 
Oidium lactis 
89. 
Spirillum rubrum 
90. 
Saccharomyces cerevisiae I 
91. 
Saccharomyces urinae 
92. 
B. pestis 
93- 
St. cereus albus 
94- 
B. Violaceus 
On examining the list of organisms contained in groups I and II, it will be 
seen that the large majority are intestinal in origin. Those of group I, viz., those 
producing the reaction of gas and acid formation, are with one or two exceptions 
obviously intestinal organisms. // is, therefore, justifiable to conclude, that when the 
reaction is obtained, it is most probably produced by organisms of intestinal origin. 
When an incomplete reaction is obtained, viz., acid formation only and no gas, 
there is still strong suspicion of intestinal pollution, as it will be seen most of the 
organisms in group II (including Typhoid, Dysentery, and Cholera) are of the same 
origin. Conversely it may be stated, that when the reaction is not present faecal 
contamination is absent. 
Practical application of the test 
To prove the practicability of this test, samples of drinking and river water 
sent to the Laboratory have been tested by this method. Similarly, various dilutions 
of crude sewage and sewage effluents have been subjected to this fermentation test. 
Comparative tests with the taurocholate agar have in many instances been made side 
by side. 
Method 
In the case of drinking water, 1 cc. of the water is added- to the broth in each 
of three separate tubes respectively, the three tubes are incubated at 42° C. for forty- 
eight hours, and the results read off. 
