THE COMPOUND H^MOLYSINS 245 



of different immune-bodies. " We observe that the different 

 phenomena which we have found correspond to relative 

 quantities of immune-bodies and alexins (at complete 

 haemolysis) may have very different causes, but that they, 

 if we regard all these factors related above, may be ex- 

 plained in an unconstrained manner." 1 On the other hand, 

 I have found that the observed phenomena may be 

 explained by assuming that the law of mass action governs 

 the equilibrium of reaction between immune-body and 

 alexin, and that no special hypotheses are necessary for 

 the special cases. It may even be regarded as very prob- 

 able that a closer investigation of the combinations ex- 

 amined by Morgenroth and Sachs would have led them to 

 a more simple explanation than that which they have pro- 

 posed. 



We have stated above that after repeated injections of a 

 poison, e.g. ricin, into the veins of an animal, e.g. a rabbit, 

 the serum of this animal contains an antitoxin, in this case 

 antiricin. If we inject this antibody into the veins of 

 another animal, e.g. a guinea-pig, this animal is said to be 

 passively immunised against ricin, i.e. its blood-serum 

 contains the injected antiricin, which slowly disappears 

 (cf. p. 4) from the blood. On the other hand, the animal 

 produces an antibody against the antiricin, as may be 

 shown by experiments with mixtures of ricin, antiricin, 

 and the anti-antiricin. Such experiments were executed 

 by Bashford, 2 who even says that some of his experiments 

 indicate analogous properties of blood from animals in- 

 jected with diphtheria antitoxin, or with antitetanolysin. 



1 Morgenroth and Sachs: Berl. klin. Wochenschrift, No. 35, p. 8 (1902). 



2 Bashford: Journ. of Pathology and Bacteriology, 9. 192 (1903). 



