376 L. D. BTJSHNELL 



the formation of the clot, with darkening at the bottom of the 

 tube; but aside from the shrinking no other change occurred. 



Indol, phenol, skatol or alcohol were not found. There was a 

 slight reduction of nitrates to ammonia. The pH as determined 

 colorimetrically in Clark and Lubs media ranged from 5.8 to 

 6.2. Cultures were all negative for the methyl-red and the Voges- 

 Proskauer reactions. 



Considerable difficulty was encountered in determining which 

 of the carbohydrates were actually fennented. The work was 

 first done by the use of Durham's fermentation tubes, using meat 

 infusion broth made sugar free by fermentation with B. saccharo- 

 lyte. This medium was placed in tubes and autoclaved. To it 

 was added 1 per cent of the carbohydrate to be examined and 

 the tubes were incubated for the detection of contamination. 

 Just before inoculation they were heated and cooled rapidlj^ in 

 running water. They were then inoculated with a large loopful 

 of a four day potato-peptone culture of the organism. The cul- 

 tures were placed over phosphorous in an anaerobic jar and 

 incubated for three days at 37°C. 



Difficulty was sometimes encountered, however, in determin- 

 ing the fermentation of such carbohydrates as lactose, inulin, etc., 

 due to the fact that the closed arm of the tube would contain a 

 bubble of gas from one to three millimeters in diameter. The 

 reaction of the medium in these cases was but little changed, 

 being sometimes made slightly acid. In other cultures, however, 

 distinct amounts of acid were formed. Hiss's serum water plus 

 these carbohydrates gave similar results. 



Table 1 shows the essential features of these tests. The " -|-" 

 indicates a distinct amount of acid or gas. If a bubble of gas is 

 present it is marked with a "b." 



From our preliminary tests it was decided that we were dealing 

 with organisms belonging to the B. sporogenes group (JVIetchnikoff , 

 1908). There were differences between the various cultures, but 

 these were not marked. Some cultures alwaj's produced a cloud- 

 ing of the medium, others grew mostly on the bottom of the tube. 

 Certain cultures produced more blackening of the egg medium 

 than others. Generally speaking all the cultures exhibited the 

 same characteristics. 



