BACILLUS AEBOGENES CAPSULATUS 455 



there is said to be more formation of gas in the tissues Rabbits are 

 more resistant to this disease, whilst they are comparatively suscep- 

 tible to malignant oedema. As in the case of tetanus, inoculation with 

 living spores which have been deprived of adherent toxin by heat does 

 not produce the disease. A toxin can be separated by filtration from 

 cultures of bouillon containing 5 per cent, glucose and a thick emulsion of 

 sterile calcium carbonate. It is fairly resistant to heat, withstanding 

 two hours at 70-75 C. without being destroyed, and it is also very rapid 

 in its action, being capable in appropriate dose of killing a horse in five 

 minutes. It is to be noted as an important fact, that while freshly 

 isolated cultures possess a high degree of virulence they may have little 

 capacity for toxin production in vitro. Grassberger and Schattenfroh state 

 that there may be an antagonism between maximum virulence and 

 maximum toxin production. 

 One of the properties of the 

 toxin is said to be a capacity 

 for killing leucocytes. 



The disease is one against 

 which immunity can be pro- 

 duced in various ways, and 

 methods of preventive inocu- 

 lation have been adopted in 

 the case of animals liable to 

 suffer from it. This subject 

 was specially worked out 

 by Arloing, Cornevin, and 

 Thomas, and later by others. 

 Immunity may be produced 

 by injection (especially by 

 the intravenous and intra- 

 peritoneal routes) with a 

 non- fatal dose of the virus 

 (i.e., the cedematous fluid 

 found in the tissues of FlG - 133. -Bacillus of quarter-evil, showing 

 affected animals and which spores. From a culture in glucose agar, 



1V v incubated for three days at 37 C. 



contains the bacilli), or by stained with weak carb ^. fuchsin . x 1000 . 

 injection with larger quanti- 

 ties of the virus attenuated 



by heat, drying, etc. It can be produced also by cultures attenuated by 

 heat and by the products of the bacilli obtained by filtration of cultures. 

 An antitoxin has been produced against the toxins of the bacillus, and 

 a method of protection in which the action of this antitoxin is combined 

 with that of the virus has been used (cf. Anthrax, p. 358). The anti- 

 toxin is said to increase the chemiotactic properties of the leucocytes. 



BACILLUS AEROGENES CAPSULATUS. 



This bacillus, though sometimes aiding in the production of patho- 

 logical changes, is chiefly of interest on account of the extensive gaseous 

 development to which it gives rise in the tissues post mortem. It was 

 described by "Welch and Nuttall in 1892 ; it is now recognised as being 

 identical with an organism found in gaseous phlegmon by E. Fraenkel, 

 and called by him the bacillus phlegmones emphysematosce. The organism 

 is a comparatively large one, measuring 3 to 6 /J. in length and having a 



