552 A CONTRIBUTION TO THE STUDY OF THE PRECIPITINS, 



The Relation of Deviation of Complement to Precipitnm. 



Moreschi, iu his first paper* on the phenomena of deviation, 

 showed that the fixation of complement appeared only as a sequel 

 of precipitation. In his second paperf he was less decided on 

 this point, but held tliat the amount of complement fixed was 

 pro()ortional to the amount of precipitate. Neisser and Sachs| 

 were of opinion that the essential feature in the deviation of 

 complement was the union of a substance (antigen) with its anti- 

 body. Gay§ regarded the precipitate as the all-important factor 

 in the fixation of complement. He found that, after the precipi- 

 tate had formed, the superfluid did not bind complement, hut 

 that the precipitate, even after thorough washing, fixed coni- 

 jDleraent. Muir and Martin|| investigated the I'elation of devia- 

 tion of complement to the precipitin test. They concluded, intei' 

 alia, that a mixture of serum and its antiserum had the property 

 of fixing or deviating complement and thus interfering with 

 hfemolysis, that the amount of homologous protein necessar}' to 

 produce a distinct deviation of complement was extremely small, 

 O'OOOOl c.c. oreven less — as a rule it was many times less than 

 the amount necessary to give a visible precipitate with the anti- 

 serum — that when a precipitate formed, the deviating substance 

 was present in the precipitate and might be so exclusive!}', and 

 that the precipitation was not essential to the deviation-pheno- 

 mena, as these could be given without the formation of a preci- 

 pitate. Welsh and Chapmanll have, however, found consistently 

 that precipitates form in 48 hours with quantities as small as 

 those employed by Muir and Martin. Stress need not be laid on 

 this point, as there is now general agreement that it is the 

 product of the interaction of antigen and antibody, and not a 



* Beil. klin. Wochenschr. S.llS!, 1905. 



t Berl. klin. Wochenschr, S.76, 1906. 



X Berl. klin. Wochenschr. S.1388, 1905. 



§ Ann. de I'lnst. I'asteur, xix., p.593, 1905. 



il Journ. of Hygiene, vi., i).265, 1906. 



U Journ. of Hygiene, vi., p.259, 1906. 



