DEVIATION OF COMPLEMENT 145 



4. RELATION OF THE DEVIATION OF COMPLEMENT TO 

 PRECIPITATION 



That the union of the two substances concerned in the 

 fixation of complement is often attended with precipitation 

 has been recognized by various observers. Moreschi in his 

 first paper states that the deviation phenomenon appears 

 only as a sequel to precipitation and stands in closest rela- 

 tion to it ; in his second publication, however, he speaks less 

 decidedly on this point, though he says that the amount of 

 complement fixed is always in proportion to the amount of 

 precipitate. Neisser and Sachs in describing the application 

 of the deviation test for differentiating the blood of different 

 species regard the results by the two methods as analogous, 

 but consider that the essential in the phenomenon of devia- 

 tion is the union of a substance and its anti-substance 

 (amboceptor). Gay speaks of the 'fixation of alexins by 

 specific serum precipitates ' and finds, as stated above, that 

 the precipitate separated and washed takes up complement. 

 We shall first state the facts which we have observed, and 

 afterwards consider their significance. 



'In the first place we may consider the relative delicacy 

 of the two reactions. All observers who have written on 

 the subject state that the deviation test is more delicate 

 than the precipitin test, and our results agree with this. 

 In making the comparison the occurrence of precipitation 

 is observed by using the same amount of anti-serum 

 (generally 0-05 c.c.) in each case along with varying amounts 

 0-01, 0-001, 0-000,1, 0-000,01 c.c., &c., of the homologous 

 serum, the volume being made up with salt solution to 1 c.c. 

 The tubes are placed in the incubator for one and a half hours 



from this cause in the work which I have published. Our views regarding 

 anti- complements, however, require revision, in view of the results estab- 

 lished with regard to deviation of complements. K.M. 

 MTJIB L 



