. 296 SPECIFIC MICRO-ORGANISMS 



sometimes resist boiling in water for 2 hours and autoclave heat 

 at 5 pounds pressure for 10 minutes. 



Strict anaerobiosis is necessary for successful culture, except 

 when B. bolulinum grows in symbiosis with aerobes. Growth is 

 best at 25-30" C, Very slight at 37°-38.5" C, and best in a m,edium 

 slightly alkaline to litmus. Gelatin is quickly liquefied and 

 abundant gas is produced in glucose media. The organism ap- 

 pears to be incapable of growth in the animal body. Cultures 

 are very poisonous whe;i injected into or fed to animals. 



The poison "Botulin" resembles in some of its properties the 

 tetanus toxin. It is destroyed rapidly at 7o°-8o° C, and pre- 

 serves its toxicity for years when dried. It is neutralized by 

 mixing with brain substance. It differs from the other pow- 

 erful toxins, however, in its ability to resist the gastric juice and 

 to poison by absorption through the alimentary canal. Forssman 

 has immunized guinea-pigs, rabbits and goats, and has obtained 

 an antitoxic serum from these animals. 



Botulism is a form of food poisoning definitely recognized as 

 such as early as 1820. The symptoms are very characteristic, 

 appearing in 18 to 48 hours after ingestion of the poisonous food. 

 There is vomiting, dryness of the mouth and constipation , motor 

 paralysis, especially early in the external ocular muscles. The 

 involvement of the central nervous system may progress to com- 

 plete motor paralysis and death. The mind is usually clear even 

 in the fatal cases. The early outbreaks of the disease followed 

 the consumption of sausage, hams, fish and other cured or pre- 

 served meats. More recently outbreaks of botulism have been 

 recognized in the United States with increasing frequency and 

 their causation has been traced not only to meat foods but to 

 various canned vegetables and even fruits. 'Dickson^ and his 

 associates have shown that commercial canners processes as well 

 as home canning methods cannot be relied upon to kill the spores 

 of CI. hotulinum if this organism happens to be present in the raw 



' Dickson, Burkeand Ward: Archives of Internal Med., igig, 24, p. 581. Refer- 

 ences to literature are given in this paper. 



