84 AIDS TO BACTERIOLOGY 



not fermented. While Stockman mentions that cultures 

 of this organism have no putrefactive odour, other ob- 

 servers describe a rancid odour due to butyric acid. A 

 stab culture in glucose gelatin grows white along the stab 

 with lateral offshoots, liquefaction and disruption of the 

 medium with gas. On glucose-gelatin plates the young 

 colonies are translucent, of a yellowish-brown colour, and 

 surrounded by a liquefied zone. Growth is abundant at 

 ordinary temperatures, but scanty at 37 C., at which 

 temperature involution forms of long twisted filaments 

 develop. Sporulation does not occur at blood-heat. 



Pathogenesis. The organism has been found in liver 

 and blood sausages, pickled and smoked meat, tinned 

 meat, preserved foods, and ham that have caused ' botul- 

 ism ' or ' sausage poisoning.' Where symptoms show 

 immediately after ingestion of the infected food they 

 are those of gastro-intestinal disorder. It is not till after 

 a period of incubation of twelve or more hours that the 

 prominent symptoms described by van Ermengem show, 

 these being disordered secretion in the nose, dryness of 

 mouth and throat, dilated pupil, ptosis, paralysis of 

 accommodation, double vision, dysphagia, aphonia, and 

 retention of the urine. Fever is absent, and no impairment 

 of intellect occurs. While marked constipation has been 

 recorded, there may be slight and transitory vomiting 

 and diarrhoea. Death, from bulbar-paralysis, follows in 

 about a quarter of the cases. 



Except for an instance where a bacillus indistinguishable 

 from B. botulinus was isolated by Kempner from the 

 intestine of a pig, there is no information as to the origin 

 of the organism. From the scanty growth obtained at 

 blood-heat it is fairly certain that little or no multiplica- 

 tion of the bacilli takes place in the living animal, so that 

 a sufferer is not a source of danger to his associates, and 

 it is pretty evident that infection of food must have 

 occurred after death of the animal, the infection coming 

 from sources outside the meat. Savage in reviewing the 

 reported cases of botulism found that in none of the out- 

 breaks had the foods incriminated been eaten in the fresh 

 state, all had been stored. There is often no external 

 sign of putrefaction in the infected meat, but it may 

 have a rancid odour. 



An extracellular toxin of extremely high potency is 



