TOXIN AND ANTITOXIN 131 



mann and Takaki discovered that emulsions of the tissue of the cen- 

 tral nervous system of rabbits and guinea pigs, shown by Meyer and 

 Ransom and others to be the special points of attack for tetanus toxin, 

 possessed the- power of neutralizing this poison in vitro, while emul- 

 sions of spleen Jddney and other organs had no such effect. They 

 assumed from this that the poison was fixed by cell receptors, ante- 

 cedents of antitoxin in the sense of Ehrlich. Kempner 34 35 made 

 similar observations with botulinus toxin and further confirmation 

 has been derived from experiments like those of Blumenthal, 36 who 

 found that the toxin was neutralized by the brain tissue of susceptible 

 animals but showed conversely that the brain substance of the 

 chicken, an animal but slightly susceptible to tetanus, possessed little 

 or no neutralizing power. Similar results were obtained by Metchni- 

 koff in the cases just cited. 



The great importance of these experiments lies not only in show- 

 ing that body cells may absorb the toxins, but that there is direct 

 relationship between the susceptibility of tissue and the toxin-bind- 

 ing properties. Furthermore the facts demonstrated by Metchnikoff 

 that no antitoxin was produced by those animals (turtle, lizard) in 

 which the tissues had no power of fixing poison and which are con- 

 sequently insusceptible, furnish powerful evidence in favor of Ehr- 

 lich's view. 



It becomes of great importance, therefore, to determine whether 

 in the case of the fixation of tetanus toxin by the brain cells the 

 union between cell and toxin is a specific and chemical one compar- 

 able in every way to the union of toxin with antitoxin. 



Metchnikoff, in spite of his results in the experiments just cited, 

 objected to this interpretation on the ground that although the brain 

 emulsion of a guinea pig neutralized tetanus toxin in vitro, the in- 

 jection of the toxin into such an animal, subdurally, produced the 

 disease. This can hardly be regarded as a valid argument against 

 Wassermann's interpretation, since the very premises of the Ehrlich 

 theory require that these neutralizing elements, when still attached 

 to the living cell, as "sessile" receptors, are the cause of the poison- 

 ing, since they serve to "unlock" the cell to the entrance of the toxin. 

 Similar objections on the part of Metchnikoff 37 were based on some 

 of his own experiments, as well as on those of Courmont 38 39 and 

 Doyen, in which it was found that the poison disappears but slowly 

 (in 2 to 3 months) from the circulation of frogs, and the brain cells 

 show hardly any toxin neutralization in vitro, whereas these animals 



34 Kempner and Pollak. Deutsche med. Woch., 1897, No. 23, p. 505. 



35 Kempner and Shepilewsky. Zeitschr. f. Hyg., Vol. 36, 1901, p. 1. 



36 Blumenthal. Deutsche med. Woch., 1898, No. 12, p. 185. 



37 Metchnikoff. Ann. de I'Inst. Past., Vol. 12, 1898. 



38 Courmont and Do^en. Arch, de Physiol., 1893. 



39 Courmont and Doyen. Compt. rend, de la soc. de biol, 1893. 



