384 MICRO-ORGANISMS AND DISEASE [chap. 



basis for the use of blood-serum of animals, artificially im- 

 munised against tetanus, for the cure of human tetanus 

 — the antitoxic power of that blood-serum — is derived ; 

 researches carried on by Behring, by Roux and Vaillard 

 (Atinales de I' Imtitut Pasteur, 1893), and others have led 

 to the obtaining of tetanus antitoxin blood-serum both for 

 protective and curative purposes {see Chapter on Im- 

 munity). 



Tizzoni and Cattani,in a series of memoirs, had already 

 demonstrated the means by which animals possessed natu- 

 rally of slight or great susceptibility respectively can be 

 made altogether insusceptible to tetanus. Further, the 

 blood-serum of animals, made previously insusceptible, 

 injected into animals possesses a decided antitoxic action. 

 They have isolated from such blood-serum this substance — 

 the tetanus antitoxin — by precipitating with alcohol, drying 

 in vacuo, and dissolving in water. In four cases of human 

 tetanus, by the injection of the antitoxin of Tizzoni the 

 disease was arrested and the patients recovered {Centralbl. 

 f. Bad. und Farasit., Band x.. No. 24, p. 785.) 



3. Bacillus of symptomatic charbon {quarter evil, Rausch- 

 brand). — This disease affecting young cattle and sheep 

 occasionally produces great mortality amongst them, par- 

 ticularly amongst the former. Owing to its involving 

 chiefly one of the hind extremities in the form of a large 

 subcutaneous tumour, in which, on incision, a quantity of 

 sanguineous, discoloured, almost black fluid is shown, the 

 disease is called quarter evil or black leg. Owing to its 

 slight resemblance to anthrax (large tumour containing 

 serous sanguineous fluid) it is, called in France charbon 

 symptomatique ; in Germany it is called Rauschbrand on 

 account of the emphysematous nature of the tumour, and 

 on account of the gangrenous nature of the infiltrated 



