ON THE FILTKATION OF SERUM 

 COMPLEMENT 



A considerable number of facts have been accumulated 

 with regard to the effect of passing organic and other solu- 

 tions through porcelain filters, though the physical processes 

 underlying such facts are far from being fully understood. 



The subject lias perhaps been most fully investigated in the case 

 of enzymes, and the literature on the subject has been collected 

 by Levy, 1 to whose paper the reader may be referred for details. 

 It is sufficient to state that various enzymes are kept back to a 

 varying extent by filtering through porcelain and other filters. 

 Levy, for example, found that rennet was completely retained by 

 a Berkefeld filter, that pepsin was partially retained, and that 

 ptyalin and taka diastase passed through. Sirotinin 2 found that 

 when a peptone solution was passed through a porcelain filter, 

 a certain amount was retained at first, but that afterwards the 

 peptone passed through freely. Similar results have also been 

 obtained with metallic colloidal solutions. Zsigmondy 3 , for example, 

 quotes the finding of Bredig that a certain amount of colloidal gold 

 is at first retained by a Pukall filter, but that later it passes through 

 freely for a time. He also makes the important observation, that 

 when a certain amount of egg-white is added to the gold solution, 

 the filter becomes permeable, a fact which is of high importance 

 in relation to some of the results obtained below. Observations 

 with regard to the constituents of the serum concerned in haemolysis 

 and bacteriolysis appear to be comparatively few. Ehrlich and 

 Morgenroth 4 , on filtering goat's serum through a Pukall filter, 

 found that the complement concerned in the natural lysis of rabbit's 

 corpuscles was retained, while that acting on guinea-pig's corpuscles 

 passed through. They also found that the normal immune-body 



1 Levy, Journ. Infect. Diseases, 1905, ii, p. 1. 



2 Sirotinin, Zeitschr. /. Hyg., 1888, iv, p. 288. 



3 Zsigmondy, Zur Erkenntnis der Kottoide, Jena, 1905. 



4 Ehrlich and Morgenroth, Studies on Immunity, 1906. 



