ACTION OF ANTITOXINS ON TOXINS. 261 



ance with the manner in which the blood is added to the serum. 

 If, for example, we add a given amount of blood in a single dose to, 

 say, 1 c.c. of serum, this amount, A, may be relatively considerable 

 and yet be entirely hemolyzed. But if this amount A is divided 

 into several fractions added one after another at sufficiently 

 spaced intervals to the same amount of the active serum, only a 



few of the corpuscles, say -, will be destroyed. It would seem 



as if the first closes of corpuscles had taken up all the hemolytic 

 substances, and so deprived the subsequently added corpuscles of 

 their share. 



A blood corpuscle, then, absorbs varying amounts of active sub- 

 stances, the maximal dose that can be fixed being distinctly greater 

 than the amount necessary to produce complete solution.* With 

 this explanation we may offer, as a preliminary hypothesis, that 

 the absorption of the active principles of serum by the fixing portion 

 of blood cells does not follow the law of fixed proportions, but 

 resembles, rather, the absorption of dyes by substances that take 

 them, which absorption varies considerably in amount. Con- 

 sequently we should expect the absorbing energy to vary to a 

 large extent, depending on the conditions of the experiment (con- 

 centration of the substance considered, length of contact, establish- 



* As we know, hemolysis depends on the collaboration of the alexin and the 

 sensitizer. To which of these two substances is this result due? In other words, 

 which one is absorbed in variable doses by the red blood cell? Both substances 

 have this property, but the alexin shows it the more distinctly; and to the alexin, 

 then, is due the greater part in the phenomenon. To a tube containing 0.5 of a 

 cubic centimeter of alexin (fresh guinea-pig serum) is added 0.3 of a cubic cen- 

 timeter of well-washed rabbit blood, and immediately afterward 0.9 of a cubic 

 centimeter of sensitizer (guinea-pig > rabbit serum, 55 degrees), hemolysis follows 

 rapidly. Three hours later 0.1 of a cubic centimeter more of blood and 0.3 of a 

 cubic centimeter of sensitizer is added, and 1 hour later 0.1 of a cubic centimeter 

 more of blood and 0.3 of a cubic centimeter of sensitizer. The last corpuscles 

 remain intact. We may then prepare a mixture containing the same total 

 amount of each substance (0.5 c.c. of alexin, 0.5 c.c. of blood and 1.5 c.c. of 

 sensitizer), but mix them together at once. Complete hemolysis occurs. The 

 intact corpuscles in the first mixture are well sensitized, but lack alexin. This is 

 shown by the fact that the subsequent addition of alexin produces complete 

 hemolysis. We may conclude, then, that the stromata of the first hemolyzed cor- 

 puscles are loaded with alexin that they refuse to yield to other sensitized corpus- 

 cles. The stroma-alexin complex is stable and does not break up. We shall later 

 return to this fact in considering one of Morgenroth's experiments. 



