THE FIXATION OF ALEXINS. 353 



the sheep corpuscles he does not state, but we may presume not 

 far differently from the manner employed in tube A, since the 

 result is the same. Tube C differs from tube A only in the fact 

 that every trace of sheep serum has been removed by the repeated 

 washings. The succeeding steps follow exactly the conditions 

 and dosage of Sachs. 



Tubes A, B and C are left at 37° C for 1 hour. Tubes A and C 

 are then centrifugalized and the supernatant treated sera as well as 

 the contents of tube B serve to make the following tubes: 



Tube l. 

 Tube 2. 

 Tube 3. 

 Tube 4. 

 Tube 5. 



Contact at 37 degrees for one-half hour. Then to each tube is 

 added 1 c.c. of a 5 per cent suspension of washed sheep corpuscles 

 (5 times) plus 0.4 of a cubic centimeter of serum rabbit > ox, 

 55 degrees (about two hemolytic doses). Resultant hemolysis is 

 as follows: 



t b i ) Tube 3 ) 



rp U i e o ( No hemolysis Tube 4 > Hemolysis complete 



iube ^ ' Tube 5 J 



That is, in rabbit serum treated with imperfectly washed sheep 

 corpuscles, there is a substance that prevents the hemolysis of test 

 corpuscles added at the end; this is the Sachs experiment. If the 

 corpuscles are washed so as to remove all sheep serum, there is no 

 antagonistic substance found. That there is an alexin-fixing sub- 

 stance present in tube "A" is true, but it is the precipitate formed 

 at the end by the interaction of the immune serum and the sheep 

 precipitinogen carried by the treated rabbit serum, and not the 

 treated serum itself. That no true " anticomplement action" 

 exists in the digested normal rabbit serum itself in the experiment 

 of Sachs is easy of proof and would have been evident in the tubes 

 of this experimenter had he only subjected the tubes which he 

 compares, to the same experimental conditions. The details of 



