ACTION OF ANTITOXINS ON TOXINS. 273 



tube. It may be presupposed that this substance will be distinctly 

 attenuated in the first mixture, and such proves to be the case 

 although the result is not very striking. If sensitized hen cor- 

 puscles are subsequently added to these tubes, hemolysis is more 

 rapid in the control than in the first tube, although the difference 

 is not extremely marked. And why? 



The first mixture contains in addition to the anti-alexin a total 

 of 0.6 of a cubic centimeter of alexin added in two successive frac- 

 tions. A comparison of the hemolytic power of this mixture with 

 that of a mixture containing 0.6 of a cubic centimeter of alexin 

 added in a single dose is interesting. 



We prepare, then, liquid A, containing 0.3 of a cubic centimeter 

 of anti-alexin plus 0.5 of a cubic centimeter of alexin. Three hours 

 later we add 0.1 of a cubic centimeter of alexin to it and at the 

 same time prepare mixture B, which contains 0.3 of a cubic cen- 

 timeter of anti-alexin plus 0.6 of a cubic centimeter of alexin. We 

 then add to each mixture 0.2 of a cubic centimeter of rabbit > 

 hen sensitizer and an hour later two drops of hen blood to each 

 tube. Hemolysis requires an hour in tube A, and an hour and three 

 quarters in B. An anti-alexic serum then neutralizes a given 

 dose of alexin better when it is added all at once than when it is 

 added in successive fractions. This experiment recalls the one in 

 which red blood corpuscles are added to a hemolytic serum either 

 all at once or in divided doses. 



In a mixture of alexin with anti-alexin the latter substance 

 is uniformly distributed over all the alexin, and all the toxic mole- 

 cules are equally modified ; the composition of the mixtures is homo- 

 geneous. But if we subsequently add more alexin to such a mixture 

 it tends to remove the antitoxin from the combination into which 

 it has entered, tends, in other words, to break up its established 

 distribution. For example, if the original complex is TA 2 , the 

 addition of another T would tend to form 2TA. But since the 

 combination TA 2 is already formed, a new reaction (i.e., removal 

 of the anti-alexin from the complex) is somewhat difficult to bring 

 about, and the additional dose of alexin, in consequence, is not read- 

 ily attenuated.* In other words, TA 2 does not give a part of its 



* If all the alexin had been added at once, the complex TA would of course 

 have been formed. 



