In a previous communication,1 the difficulties involved in the production of peritonitis and especially of fatal peritonitis were pointed out. It was found2 that in dogs the intraperitoneal injection of virulent colon bacilli suspended in gum tragacanth always produced peritonitis which was invariably fatal. The purpose of this investigation was to determine the possibility of inducing active immunity against this type of fatal peritonitis.
EXPERIMENTAL WORK
Immunization with B. Coli Communis by the Peritoneal Route.
—Twelve dogs were injected intraperitoneally with twenty-four hour cultures of Bacillus colicommunis in 0.9 per cent sodium chloride. In all these experiments B. colicommunis 3003 was used. Four injections were given, the intervals between successive ones being three days. The initial dose consisted of the saline washings of one agar slant, and the remaining three doses of two, three and four agar slants, respectively.Nine of the twelve animals were injected with living and three