356 Chapter XII 



immunised animal is antitoxic, though to a less degree. On the 

 other hand, the saliva and urine exhibit very little antitoxic power, 

 even when they are derived from animals hyperimmunised against 

 tetanus toxin. Milk, as first demonstrated by Ehrlich 1 , is fairly rich 

 in antitoxin, although much less so than the blood. According to 

 the estimation of Ehrlich and Wassermann 2 , in the same immunised 

 [374] animal, milk contains one-fifteenth to one-thirtieth of the amount of 

 diphtheria or tetanus antitoxin contained in the blood. Pus is always 

 less antitoxic than blood or blood serum. According to Roux and 

 Vaillard (/. c., p. 82), the pus of their rabbits vaccinated against 

 tetanus toxin was only one-sixth or one-eighth as antitoxic as the 

 serum of the blood. In Salomonsen and Madsen's 3 antidiphtheritic 

 horse the cellular sediment of the pus was about one-half as antitoxic 

 as the blood. 



For the development of the antitoxic property in the fluids of the 

 body, it is not essential that animals should belong to species sus- 

 ceptible to the corresponding toxin. Animals naturally most refrac- 

 tory against the poisons of diphtheria and tetanus are also capable 

 of producing antitoxins. Vaillard 4 demonstrated this fact in the 

 fowl. This bird, which is naturally refractory against tetanus, usually 

 acquires a very marked antitetanic power in its blood after one 

 or more injections of tetanus toxin. He observed, however, that, 

 in fowls thus treated, at a stage when the fluids of the body are anti- 

 toxic, the albumen of the egg is not so. The antitoxin, therefore, 

 does not pass into this nutritive secretion, as it does into the milk 

 of mammals. On the other hand, as has been demonstrated by 

 F. Klemperer 5 , the vitellus of the eggs of fowls treated with tetanus 

 toxin in time acquires an antitoxic property of the most marked 

 character. 



The antitoxins, found especially in the fluids of the body but 

 only scantily in the cells, exert some action on the toxins. What 

 is the nature of this action? This question, much studied and 

 discussed, is one of very great importance in connection with the 

 general problem of acquired immunity against toxins. In his first 

 memoir, written in collaboration with Kitasato, von Behring (Deutsche 



1 Ztschr.f. Hyg., Leipzig, 1892, Bd. xii, S. 183. 



2 Ztschr.f. Hyg., Leipzig, 1894, Bd. xvm, S. 248. 



1 Ann. de VInst. Pasteur, Paris, 1 897, t. xi, p. 324. 



4 Compt. rend. Soc. de UoL, Paris, 1891, p. 462 ; Ann. de VInst. Pasteur, Paris, 

 1892, t. vi, p. 229. 



5 Arch.f. exper. Path. u. Pharmakol, Leipzig, 1893, Bd. xxxi, S. 371. 



