Pathogenesis 349 



change. In discussing these changes Ernst concluded that they 

 were ante-mortem and due to the irritation caused by the bacillus. 

 The gas-production he regards as post-mortem. 



In the internal organs the bacillus is usually found in pure culture, 

 but in the wound it is usually mixed with other bacteria. On this 

 account it is difScult to estimate just how much of the damage be- 

 fore death depends upon the activity of the gas bacillus. That 

 gas-production after death has nothing to do with pathogenesis 

 during life is shown by injecting into the ear-vein of a rabbit a 

 liquid culture of the gas bacillus, permitting about five minutes' 

 time for the distribution of the baciUi throughout the circulation, 

 and then killing the rabbit. In a few hours the animal will swell 

 and its organs and tissues be riddled with the gas bubbles. 



At times, however, as in a case of Graham, Stewart and Baldwin, 

 there is no doubt but that the bacillus produces gas in the tissues 

 of the body during life. These observers, in a case of abortion with 

 subsequent infection, found the patient "emphysematous from the 

 top of her head to the soles of her feet" several hours before death. 



In this case, in which the bacillus was found in pure culture, 

 it would indeed be difficult to doubt that the fatal issue was due to 

 Bacillus aerogenes capsulatus. 



An excellent review of the early literature of the -subject is to be 

 found in "A Contribution to the Knowledge of the Bacillus Aero- 

 genes Capsulatus," by W. T. Howard, Jr.* 



Immunity and Specific Therapy. — Few experiments along these 

 lines have resulted in anything worthy of much attention until 

 Bull and Pritchettf found that under certain conditions Bacillus 

 aerogenes capsulatus gives off a soluble toxin that can be utilized 

 to make an antitoxic serum by administration to animals, and laterj 

 that when such a serum was prepared by the immunization of horses, 

 it was capable of conferring an immunity upon animals that was of 

 about two weeks' duration. It is believed by the investigators that 

 such serum could be used to prevent gaseous wound infection in 

 man. 



Other Micro-organisms of Gaseous Infections. — Elhott and 

 Henry§ in studying cases of infection of hemothorax by anaerobic 

 gas-producing baciUi, found the following: 



1. Bacillus perfringens group. — These include: 

 Bacillus perfringens (Veillon and Zuber). 

 Bacillus aerogenes capsulatus (Welch). 

 Bacillus enteritidis sporogenes (Klein). 

 Bacillus of articular rheumatism (Achaline). 

 Bacillus phlegmonis emphysematose (Fraenkel) . 

 Bacillus saccharobutyricus immobilis (Schattenfiroh and Grossburger). 



* "Contributions to the Science of Medicine bv the Pupils of W. H. Welch," 

 1900, p. 461. 



t "Jour. Exp. Med.," 1917, xxvi, p. 119. 

 I" Jour. Exp. Med.," 1917, xxvi, p. 603 

 I Brit. Med. Jour.," 1917, i, p. 413. 



