RELATIONS OF SENSITIZERS TO ALEXIN. 383 



Tube a. Ten per cent suspension of guinea-pig corpuscles, 

 1 c.c. 



Tube b. Ten per cent suspension of corpuscles, 1 c.c.; fresh 

 horse serum, 0.3 c.c. 



Tube c. Suspension of corpuscles, 1 c.c.; bovine serum (56 de- 

 grees), 0.3 c.c. 



An hour later the tubes are filled with salt solution, the mixtures 

 well shaken and centrifugalized. The supernatant fluids are then 

 decanted and 1 c.c. of salt solution is added to each sediment. To 

 tubes "a" and "b" is then added 0.3 of a cubic centimeter of bovine 

 serum (56 degrees), and to tube "c" 0.3 of a cubic centimeter of 

 fresh horse serum. As a result, there is a powerful and almost 

 immediate agglutination in "6," but nothing of the kind in "a" 

 or "c." 



Sixth: According to the preceding results we should expect that 

 horse serum that has been treated with guinea-pig corpuscles would 

 be deprived both of its sensitizer and of its alexin for these cells, and 

 that consequently it would have no power to form an agglutinating 

 and hemolytic mixture for fresh guinea-pig corpuscles with bovine 

 serum. This exhaustion of horse serum by contact with guinea- 

 pig corpuscles is easily verified experimentally, as Klein* has already 

 shown. This fact, moreover, is quite irreconcilable with Ehrlich and 

 Sachs' explanation. There is one fact, however, that must be 

 noted in performing this experiment. The absorption of the active 

 substances from horse serum takes place perfectly if the serum is 

 mixed with a suspension of corpuscles, that is to say, corpuscles 

 sufficiently diluted in salt solution. But if the salt solution is 

 removed, that is, if a sediment of corpuscles is employed, the absorp- 

 tion is incomplete and the serum retains the larger part of its 

 original properties. This fact has also been noted by Klein. This 

 would show that the fixation of active principles in a serum is in- 

 fluenced by very slight variations, the importance of which well 

 may be overlooked, and, consequently, the usual method of specific 

 absorption as employed by Ehrlich and his followers in the study 

 of hemolysis may lead to erroneous conclusions. In the present 

 example, for instance, one might be led to conclude that the cor- 



* Ueber die Beeinflussung des hamolytischen Komplements durch Agglutina- 

 tion und Prazipitation. Wiener klinische Wochenschrift, 1905, No. 48. 



