EDWIN O. JORDAN 449 



production and persistence of botulinum toxin in canned foods must concur relatively 

 seldom. Numerous instances are on record in which the presence of botulinum toxin 

 has been demonstrated in certain jars or cans of food while other jars or cans of the 

 same lot preserved at the same time and to all appearances in the same manner have 

 proved free from toxin. Among the factors that tend to prevent the production of 

 botulinum toxin are an unsuitable reaction of the culture medium, the maintenance 

 of an unsuitable temperature for germination, the presence of only a scanty number 

 of uninjured spores, and the simultaneous presence of other organisms such as CI. 

 sporogenes^ Even when once formed, the toxin of CI. botulinum may sometimes be 

 destroyed by the growth of CI. sporogenes and certain other anaerobes.^ 



The opinion of some of the earlier investigators that CI. botulinum "is absolutely 

 incapable of reproducing itself in the animal body" does not seem to be warranted 

 by recent studies. Coleman and Meyer^ and Starin and Dack^ have found that under 

 certain conditions detoxified spores are capable of germination in the bodies of 

 laboratory animals, that spores and vegetative forms may become widely dissemi- 

 nated through the tissues, and that toxin may be formed in sufficient quantity to 

 cause death. It is highly improbable, however, that under natural conditions tissue 

 invasion by living botulinum organisms is ever the cause of botulism in man. Enor- 

 mous doses must be used to produce this effect in experimental animals, and no in- 

 stance is known of the development of botulism in man except when formed botulinum 

 toxin has been taken into the alimentary tract. 



The absorption and mode of action of botulinum toxin are quite obscure. Al- 

 though botulinum toxin is unicjue in being the only known exotoxin that is absorbed 

 from the digestive tract, the amount necessary to produce death is much larger by 

 mouth than by other routes. Swine resist enormous doses given orally. 



Death from botulism is practically always due to failure of the respiratory muscles 

 or of the heart, more often the former. Dickson and Shevky^ have observed that the 

 toxins of both Types A and B affect the peripheral endings of the motor fibers. There 

 is no demonstrable change in smooth and striated muscles. 



In animal experimentation antitoxin may be produced by properly graduated 

 inoculations of botulinum toxin just as with tetanus and diphtheria toxin, and has 

 proved efficacious in preventing the death of animals from experimental botulism. 

 Type A toxin is neutralized by Type A but not by Type B antitoxin; Type B toxin, 

 however, seems to be slightly weakened by large quantities of Type A antitoxin.'' 

 The therapeutic value of botulinum antitoxin has never had a fair test with human 

 patients. The early development of symptoms and the fact that the antitoxin (owing 

 largely to the rarity of the disease) is not usually at hand stand in the way of prompt 

 administration. 



■ Jordan, E. O., and Dack, G. M.: J. hifect. Dis., 35, 376. 1924. 

 = Dack, G. M.: ibid., 38, 165. 1926. 



3 Coleman, G. E., and Meyer, K. F. : ibid., 31, 662. 1922. 

 "Starin, W. A., and Dack, G. M.: ibid., 36, 383. 1925. 



s Dickson, E. C, and Shevky, E.: /. E.xper. Med., 38, 327. 1923, 



4 Jensen, L. B.: ./. Infect. Dis., 39, 413. 1926. 



