DEVIATION OF COMPLEMENT 135 



tity (0-000,01 c.c.) of the original normal serum added to the 

 anti-serum may result in the taking up or deviation of 

 various complements. From his experiments he has found 

 reason to doubt whether there is any real anti-complement 

 in the strict sense, i.e. a substance which unites directly 

 with a complement and thus prevents its action, the appar- 

 ently anti-complement action being a deviation phenomenon. 

 Neisser and Sachs 1 have applied Moreschi's results to the 

 differentiation of the bloods of different species of animals, 

 and have shown that the deviation of complement is a much 

 more delicate test than the precipitation test ; that is, a 

 much smaller amount of the serum (precipitinogen) when 

 added to the anti-serum (precipitin) will produce a deviation 

 or fixation of complement than that necessary to cause a 

 visible precipitate. They consider that the phenomenon is 

 analogous to the fixation of complement by a cell-receptor 

 when combined with its corresponding amboceptor. Gay 2 

 regards the precipitate as the all-important factor in the 

 fixation of complement, and finds that when a precipitate 

 forms the separated fluid is without effect on complement, 

 whilst the precipitate fixes or combines with a considerable 

 quantity. He extends his observations with the purpose of 

 showing that the phenomenon of deviation in haemolytic and 

 bactericidal experiments may depend upon fixation by 

 precipitate. Pfeiffer and Moreschi 3 have found that the 

 precipitate, by fixing complement, has an anti-bacteriolytic 

 action in the animal body. In a second communication on 

 anti-complements Moreschi 4 considers the quantitative rela- 

 tionships between the serum and anti-serum (precipitinogen 



1 Neisser and Sachs, Berlin. Uin. Wochenschr., 1905, No. 44, and 1906, 

 No. 3. 



8 Gay, CentrolU. /. Bakteriol, Abtheil I., Originate, 1905, vol. xxxix, 

 p. 603 ; Annales de VInst. Pasteur, 1905, p. 593. 



8 Pfeiffer and Moreschi, Berlin. Uin. Wochenschr., 1906, p. 33. 



4 Moreschi, ibid., 1906, p. 76. 



