Bacillus botulinus was first isolated by van Ermengem1 who recovered it from meat that had produced an epidemic of botulism. He demonstrated that a soluble toxin secreted by the bacillus in the food was responsible for the condition and that the organism itself had no pathogenic power. That is to say, the bacillus was unable to produce the toxin under the conditions existing in the body.
The bacillus described by van Ermengem was a motile, sporulating anaerobe. This organism fermented dextrose, but did not coagulate milk. It required the presence of peptone in a neutral or slightly alkaline medium for toxin production. At temperatures above 30 C. toxin formation was inhibited. (This latter fact alone explained its lack of pathogenicity in animals having a temperature of 37 C.)
Although an obligatory anaerobe when in pure culture, van Ermengem and others showed that B. botulinus produced its toxin in the presence