388 J. RUSSELL ESTY 



in large amounts, as is detected by its characteristic odor. 

 Litmus milk turns from blue to red very rapidly after inocula- 

 tion upon incubation showing the increase of acidity. 



5. Potato. Clostridium Welchii was grown in broth tubes 

 containing pieces of potato and sterilized under oil. Gas pro- 

 duction was rapid and growth was abundant in twenty-four 

 hours. The starch was so vigorously attacked in some cases 

 that the potato was penetrated by the organism. The colonies, 

 which appeared on the potato, were thin, moist and grayish- 

 white on the surface and through the pieces. No spores were 

 demonstrated in this medium, either microscopically or experi- 

 mentally. 



6. Blood serum. Growth is abundant on the smeared surface 

 of blood serum after twenty-four hours incubation at 37°. Diges- 

 tion of the medium soon takes place, changing the consistency 

 of the coagulated serum and liquefying it completely in from 

 four to six days. Cultures live in this medium for at least six 

 months, spores appearing first on the sixth day of incubation. 



The colonies on blood serum appear round, about 7 mm. in 

 diameter, opaque grayish-white with finely granular edges some- 

 what frayed. A foul odor is given off after several days growth. 

 These facts are based on experiments with 20 strains of Clostri- 

 dium Welchii isolated from market milk and inoculated on 

 Loeffler's blood serum. 



VIII. CHEMICAL CHARACTERS 



1. Action on carbohydrates, a. Gas production. With all the 

 monosaccharides, disaccharides and polysaccharides used, 100 

 per cent of gas is produced, the time required for such production 

 being from eighteen to thirty-six hours. In nearly every case 

 little or no gas is formed after forty-eight hours. Inulin is 

 fermented in some cases but mannitol and glycerol are never 

 fermented by any strain of this organism. 



b. Acid production. The amount of acid produced by the 

 growth of Clostridium Welchii in sugar media ranges from less 

 than 1 to 12 per cent as determined by titrating against -& alkali, 



