116 SPECIAL BACTERIOLOGY 



of malignant oedema. It also differs in its reaction towards animals. 

 Cattle, while susceptible to symptomatic anthrax, are practically immune 

 to malignant oedema. Swine, dogs, rabbits, pigeons, and chickens are 

 readily affected by malignant oedema, but not as a rule by symptomatic 

 anthrax. According to Arloing, frogs can be inoculated if kept at a 

 temperature of 22 C. Horses are affected only locally and not seriously 

 with symptomatic anthrax, but are conspicuously susceptible to both 

 artificial inoculation and material infection by the bacillus of malignant 

 oedema. The distribution of the organisms over the earth's surface is 

 also quite different, malignant oedema being present in almost all 

 soils, while symptomatic anthrax appears confined to certain localities, 

 especially places where infected herds have been pastured. Natural 

 infection occurs principally in young cattle ; next in order being sheep 

 and goats ; whilst in mankind a genuine case is not recorded. 



The ordinary manner of infection is by wounds which not only tear 

 the skin, but penetrate the subcutaneous tissue. The disease is also 

 produced by the ingestion of forage soiled by very active virulent 

 matters, and by the inhalation of dust charged with dried virus. 



Vaccination. Animals sometimes inoculate themselves accident- 

 ally, and as small doses cause immunity this immunity being trans- 

 mitted from the mother to the foetus the result is that part of 

 the animals exposed to contagion escape its fatal effects. The 

 French recommend the successive employment of two vaccines pre- 

 pared from material from a fresh lesion spread out thinly, and dried 

 at 35 C., and then a sufficient quantity of this powder is triturated 

 in a mortar with 2 parts of water, and exposed to 100 to 104 C. 

 for the first vaccine, and 90 to 94 C. for the second, during seven 

 hours ; when the dry vaccines are taken from the oven 1 centigram 

 of the powder is diluted in J c.c. of water for each animal. The 

 vaccine prepared at 100 is used first, and the second in eight days. 

 The inoculation is made in the cellular tissue of the ear, or on the 

 internal face of the end of the tail, the second inoculation a little 

 above the first. Kitt recommends a single vaccine from infected flesh 

 heated six hours at 100 C., given in decigram doses, injected in the 

 subcutaneous tissue near the elbow. Animals can also be vaccinated 

 with natural virus either in the cellular tissue or intravenously ; when 

 the latter method is adopted great care must be taken to avoid 

 inoculation of the surrounding tissue. Attenuated viruses are there- 

 fore generally preferred for the production of immunity. 



TETANUS. 



(FMg. Lockjaw; Ger. Wundstarrkrampf ; Fr. Tetanos.) 

 This disease occurs in all the domestic animals and in man. The 



