366 VETERINARY BACTERIOLOGY 



Immunity. The toxin produced by Bacillus botulinus is among 

 the most powerful known 0.00005 to 0.0001 gm. is fatal in 

 three to four days when injected subcutaneously into a guinea-pig, 

 and 0.0001 to 0.0005 gm. will destroy a rabbit. A most striking 

 characteristic of this toxin, and one which distinguishes it from 

 those of diphtheria and tetanus, is its ability to produce poisoning 

 when taken into the body by way of the alimentary tract. Guinea- 

 pigs, and even apes, are killed by the ingestion of 0.01 c.c. of a 

 dextrose broth-culture solution in which the organism has been 

 grown. The toxin is destroyed by exposure to light and air. 

 Hoating to a temperature of 80 renders it non-toxic. Antitoxin 

 has been prepared from the goat and from the horse by gradually 

 increasing doses of the toxin. This antitoxin exerts both a pro- 

 phylactic and a curative effect when injected. The poisoning 

 by B. botulinus is so infrequent, however, that the antitoxin is 

 only of scientific value. 



Bacteriological Diagnosis. This can be accomplished only by 

 isolation and cultivation of the specific organism. 



Transmission. The organism has been isolated, not only 

 from poisonous meat, but from normal swine feces as well. The 

 disease can be produced only by the ingestion of proteins in which 

 the organism has been growing. 



