294 31anual of Veterinary Microbiology. 



to have successfully used it in the treatment of human 

 tetanus. 



Vaillard, by injecting into the blood of rabbits, 

 first, in several doses, 40 cc. of filtered culture heated 

 to 58°, second, 10 cc, of filtered culture heated to 51°, 

 and, finally, 15 cc. of filtered culture not heated, did 

 not immunize these animals, but communicated to 

 their blood the toxinicidal power; hence it follows 

 that there is no relation between the toxinicidal 

 property and the refractory state.* 



* [Of the more recent investigations bearing on the etiology of 

 tetanus and the production of immunity, the following points 

 may be briefly noted : 



The necessary co-operation of other microbes at the place of in- 

 fection (in the naturally acquired disease) has been reaffirmed. 

 (Vaillard and Rouget.) 



According to Courmont and Doyon, the special tetanus toxine 

 results from a fermentation excited in certain tissues of the or- 

 ganism by a soluble ferment secreted by the bacillus tetani. 

 {Compt. rend. Soc. cle Blologie, March, 1893.) 



Immunity can be obtained by repeated injection of cultures of 

 the bacillus tetani grown in bouillon prepared from the thymus 

 gland of calves, or of filtered cultures to which a certain propor- 

 tion of an extract of this gland has been added (Brieger, Kitasato, 

 etc.) ; the blood serum of animals thus immunized possesses im- 

 munizing properties. By repeated injection of gradually increas- 

 ing doses of virulent cultures to animals (rabbits, dogs, horses) 

 which have been thus immunized, the protective power of the 

 serum of these animals becomes greatly increased. This serum 

 then furnishes an effective " vaccine." The serum of such im- 

 munized animals or a preparation from the same (anti-toxin : Tiz- 

 zoni, Cattani) has been used (by repeated subcutaneous injection 

 of considerable doses) in the treatment of tetanus in man, and 

 apparently with good results. (Ref. Centralhl. f. Bacteriologie, XIII, 

 4,14; XIV, A, 12, 19; XV, A.) 



The curative action of the serum of immunized animals de- 

 pends upon its immunizing properties ; it localizes the tetanus 



