CHAPTER XIII 



SYMPTOMATIC ANTHRAX 



History. Under various names, such as "blackleg," "quarter evil" 

 in English ; "Charbon Symptomatique" in French ; and "rauschbrand" 

 in German, this disease has been a cattle scourge for centuries. We 

 owe our first and most valuable knowledge concerning it to French 

 investigators. As early as the eighteenth century it was shown by the 

 studies of Chabert and Boutrolle to be a specific disease. The most 

 thorough studies of the nineteenth century were made by Arloing, 

 Cornevin and Thomas of Lyons. As early as 1879 these men recog- 

 nized the infectious nature of the disease and began their work on the 

 bacillus, the pathology and the immunology of this pest. It is con- 

 fined to cattle and no case of infection in man has been observed. 



The Bacillus. This organism is generally known as Bacillus 

 chauvei, from the distinguished French veterinarian Chaveau. It is 

 a large, spore-forming anaerobic bacillus, sometimes growing in chains, 

 but usually in separate rods. The diameter of the spores being much 

 greater than the breadth of the rod and the location being at or near 

 the middle, the spore-bearing rod has a peculiar appearance well 

 designated as "snowshoe" or "whetstone." In old cultures free spores 

 may be seen and sometimes are numerous. The spores are highly 

 resistant to heat and chemical disinfectants, and when a locality 

 becomes infected eradication of the disease is not easy. This organism is 

 is not nearly so virulent as the anthrax bacillus, one rod of which suffices 

 to infect a guinea-pig fatally, while many hundred rods of the symptom- 

 atic anthrax bacillus may fail to induce a like result. Infection fol- 

 lows subcutaneous and intramuscular injections. In guinea-pigs the 

 period of incubation after artificial inoculation runs from twelve to 

 twenty-four hours, depending on the amount and virulence of the cul- 

 ture employed. The animal ceases to feed and soon begins to develop 

 an edematous area about the point of inoculation. However, if this 

 be directly on the back, the edema is more marked on the sides than 



