BACILLUS BOTULINUS 551 



extra-cellular toxins of diphtheria and tetanus. Its action is specific and it 

 always gives rise to symptoms of botulism ; moreover the illness which 

 follows its administration is always preceded by an incubation period. 



Preparation. The toxin may be prepared by any of the methods described for 

 the preparation of tetanus toxin. 



Properties. The toxicity of the toxin is lowered by exposure to light and air 

 and by heating at 58 C. for 3 hours. Its properties are destroyed altogether by 

 heating at a temperature of 100 C. 



The toxin is highly poisonous. For man the lethal dose is said to be 0*035 mg. ; 

 rabbits succumb in 72 hours and guinea-pigs in 4-5 days after being inoculated 

 with quantities of 0'005 c.c. ; in cats a dose of 0'5 c.c. of a filtered culture produces 

 the characteristic symptoms of botulism and death takes place in about 8-10 days. 



The toxin acts specifically on the nervous system. 



Kempner and Pollack, and Marinesco have demonstrated changes of toxic degenera- 

 tion in the anterior columns of the cord. Kempner and Schepilewski have shown 

 that the toxin combines with the tissues of the brain and spinal cord and that an 

 emulsion of these tissues has the property of neutralizing the toxin cf. Wasser- 

 mann and Takaki's experiments on tetanus toxin (p. 542). 



Charrin and Bardier have shown that the toxin acts also specifically on the heart. 



Antitoxin. Kempner by adopting the ordinary procedure (vide Diphtheria 

 and Tetanus) has been able to prepare an antitoxic goat serum. Unfortunately 

 it would appear that to obtain any curative effect in animals the antitoxin 

 must be administered within 12 hours of the administration of the toxin so 

 that it seems probable that the use of the antitoxin in medical practice will 

 not yield any very striking results. 



