230 



Professor Svante Arrhenitis 



[June 9, 



Another experiment indicates that a similar equilibrium also 

 takes place outside the ])lood-corpuscles. If we mix a certain 

 quantity of alexin with different quantities of immune-body, and let 

 the mixture remain for half an hour at 87" C, and thereafter let 

 it act upon the corresponding blood-corpuscles, we find a maximum 

 action at a certain medium concentration of the immune-body. This 

 is explained in the following manner. If no immune-body is present 

 the action is zero and it increases therefore, to begin with, with the 

 quantity of immune-body used. The hemolysin formed is dissociated 

 in a rather high degree, and the constituents alexin and immune-body 

 diffuse into the red blood-corpuscles and are absorbed there and form 

 the hemolysin. If the immune-body is present in great excess the 

 alexin is nearly wholly consumed for the formation of hemolysin, 

 therefore it diffuses very slowly and in small quantities into the red 

 blood-corpuscles, so that only insufficient quantities of hemolysin are 

 formed in them. Of course new" molecules of hemolysin dissociate 

 and deliver new quantities of alexin, but this decomposition goes on 

 rather slowly. Therefore during the time of action (2 hours at 37° C), 

 the quantity of hemolysin formed in the blood-corpuscles is insufficient. 

 Evidently there must be a maximum of action when the immune-body 

 and the alexin are present in equivalent quantities, and that is really 

 what has been found experimentally. This phenomenon, which has 

 been called "diversion of the alexin," was found by Neisser and 

 Wechsberg in investigations regarding bacteriolysins. The corre- 

 sponding phenomenon with hemolysins was eagerly sought for but 

 not found until I made some quantitative experiments with red 

 blood-corpuscles from an ox, immune-serum from an injected rabbit, 

 and guinea-pig-serum as alexin. It was not observed in other com- 

 binations investigated by me, and it is not very prominent, so that it 

 was necessary to use quantitative measurements on the degree of 

 hemolysis. The red blood-corpuscles were very carefully washed in 

 • 9 per cent, sodium-chloride solution, and thereby freed from the 

 accompanying serum. If that had not been the case the simultaneous 



