TETANUS TOXIN NEUTRALIZED BY BRAIN SUBSTANCE. 359 



"0.008 cc. tetanus poison No. 3 + 0.2 cc. brain; one hour later, 

 Viooo antitoxin unit. Tetanus poison No. 3 is very powerful. 

 1 cc. equals 5 million mouse. 15 mouse is a fatal dose for a mouse; 

 in the experiment, therefore, 40,000 mouse or more than 2600Xthe fatal 

 dose is employed, which quantity, to be sure, is neutralized by Yiooo 

 antitoxin unit. According to Wassermann, however, 1 cc. emulsion 

 can at the most neutralize 10 fatal doses; according to others, from 

 30 to 100 fatal doses. Usually 1/5 cc. suffices to neutralize not over 

 20 doses of poison, an amount which is very minute when 2600 doses 

 of poison are concerned." 



It should also be mentioned that Blumenthal and Wassermann l 

 opposed Gruber's view. Blumenthal called attention to the fact 

 that when brain substance is added to a toxin solution it is possible 

 by centrifuging to show that the original toxin solution has been 

 robbed of its toxic power, a result which cannot be obtained with 

 boiled brain. He also reminded his readers that he had shown how, 

 by introducing the toxin in vivo, the power of the brain to neutralize 

 poison had been diminished, as was seen on testing the same post- 

 mortem. This diminution was due to the union of the brain sub- 

 stance with the toxin, and was in proportion to the amount of poison 

 injected. 



Wassermann too is still convinced that there is a chemical union. 

 His view is also borne out by the fact that in the rabbit, in which, 

 according to the researches of Donitz and Roux, an extensive dis- 

 tribution of receptors capable of binding tetanus toxin was to be 

 assumed, other organs besides the brain are also capable of neutraliz- 

 ing the poison in vitro. This is in direct contrast to the guinea-pig 

 in which only the brain possesses this power. 



In view of all this we determined to finally decide whether on the 

 addition of brain to tetanus poison there is an actual union of poison, 

 and whether if this is so there is a summation of neutralizing actions 

 of brain and antitoxin. Our old studies were therefore again taken up. 

 We began with the re-examination of Kitashima's experiments, but 

 under such conditions that the errors which, independently of us, 

 Paltauf had already pointed out, namely, the employment of too 

 large doses of poison, were avoided. 



1 Deutsche med, Wochensch. 1902, Vereinsbeilage, No. 3. 



