384 MANUAL OF BACTERIOLOGY. 



animals produce variable and uncertain results. Subcutane- 

 ous injection may lead to pus-formation; in rabbits and 

 guinea-pigs injections may produce death apparently from 

 poisons introduced. With the blood of immunized animals a 

 serum-reaction, similar to that described for typhoid fever, 

 may be demonstrated. 



Concerning the occurrence of the Bacillus coli communis 

 in the intestine of man see page 164.* 



At autopsies on human subjects the great viscera are often 

 found to have been infected by the colon bacillus, usually when 

 some lesion of the intestine existed simultaneously, but in most 

 cases without having produced much apparent damage to the 

 organs invaded. The Bacillus coli communis frequently 

 occurs in mixed infections, as in wounds, inflammations and 

 abscesses. It is often found in the peritoneum in peritonitis, in 

 the pus in appendicitis, and in the urine in cystitis; it fre- 

 quently occurs in the interior of gall-stones with whose for- 

 mation it may be connected,! as first pointed out by Welch. 



There is a large number of more or less closely related 

 organisms which go by the name of the "colon group." The 

 limits of the colon group are extremely ill-defined. J 



Detection of Bacillus Coli Communis in Water. — To each of a number of 

 fermentatiou-tubes containing i per cent, dextrose-bouillon add some of the 

 suspected water (o.i to i c.c. or more). Place in the incubator. Each day 

 mark the amount of gas that has formed in the closed arm. After two days 

 B. coli communis should render the bouillon strongly acid and produce about 

 50 per cent, of gas (30 to 70 per cent, according to different writers). The 

 gas is approximately H two parts, and CO 2 one part (see page 132). From 

 tubes showing these characters plates may be made and the usual tests for 

 the colon bacillus appUed. § (See Part IV.) Stokes recommends adding the 

 water to fermentation tubes containing i per cent, lactose-bouillon and neutral 

 red (10 c.c. of a 5 per cent, solution of neutral red to a liter of bouillon); if 

 the colon bacillus is present, 30 per cent, to 50 per cent, of gas is formed (con- 



*See also Moore and Wright. Bacillus coli communis in the Domesticated 

 Animals. American Medicine. March 29, 1902. 



tLartigau. Journal American Medical Association. April 12, 1902. 



JRivas. Journ. Med. Res. XV. igo6. pp. 397-509. 



§Theobald Smith. American Journal Medical Sciences. Vol. CX. 1895. 



