4:78 CHEMISTRY OF THE LEUCOMAINS. 



He furthermore obtained immunity by applying the method em- 

 ployed by Roux and Vaillard in their work on tetanus, that is, by 

 repeated injections of the venom mixed witt gold chlorid, or sodium 

 or calcium hypochlorite. The serum of the immunized animal was 

 found to be antitoxic in the same sense as the serum of animals im- 

 munized to diphtheria or tetanus. Furthermore, not only was the 

 blood shown to be antitoxic to the venom employed, but also to the 

 venoms of other serpents. Thus, the serum of a rabbit immunized 

 against the cobra venom is not only antitoxic to this venom, but also 

 to the viper of France, the black snake of Australia, etc. 



Immunity, therefore, to venom can be obtained (1) by repeated 

 injections of small doses (Sewall, Phisalix and Bertrand, Calmette); 



(2) by the use of heated venom or vaccine (Phisalix and Bertrand); 



(3) by repeated injections of venom mixed with hypochlorite solution 

 (Calmette); (4) by injections of antitoxic serum (Phisalix and Ber- 

 trand, Calmette). The immunity according to the first method, by 

 tolerance, has been shown to be due to the presence of antitoxin sub- 

 stances in the blood (Phisalix and Bertrand, Calmette, Fraser). 

 The second and third methods are explainable in the same way. 



The application of the latter principle in the treatment of bites 

 from serpents was suggested by Phisalix and Bertrand and carried 

 out by Calmette, The rabbit, dog (?), guinea-pig (Phisalix and 

 Bertrand), horse and ass have been employed to furnish serum anti- 

 toxic to venom. Calmette has prepared a serum of a strength of 

 1 : 10,00D ; that is, rabbits given a dose of venom sufficient to kill 

 in three or four hours are saved if a quantity of antitoxic serum cor- 

 responding to iTj-jTnr ^^ their weight is injected not later than one 

 hour after the injection of venom. As stated above, this antitoxic 

 serum protects against all venoms. 



Calmette has also shown that the ichneumon of the Antilles is 

 naturally immune to venom, and that it owes this condition to the 

 antitoxic property of its blood. Just as the serum of man or of the 

 horse was sometimes found to be antitoxic to the diphtheria poison, 

 so the serum of dogs was occasionally found to be antitoxic to 

 venom. 



The studies of Phisalix * and others show that protection against 

 viper venom may be secured by the injection of serum of diverse 

 origin. The serum of the vipers, garter-snakes, eels, hedge-hog, 

 guinea-pig, frog, toad, dog and horse possesses such action. More- 

 over, Fraser has found that minute quantities of bile possess a like 

 action. Phisalix has not only confirmed this observation but has 

 demonstrated that the bile acids, oholesterin and tyrosin vaccinate 

 against viper venom. The protecting property however is lost when 

 the material is heated to 120°. The alcoholic precipitates produced 



1 Gmvpt. Rmdm, 121, 745 ; 122, 1439 ; 123, 1305 ; 125, 121, 977, 1053 ; 127, 

 1036 ; 126, 431. 



