FURTHER DEVELOPMENT OF KNOWLEDGE 179 



in the case of bacteriolysis), must be attributed to failure of func- 

 tionation on the part of the complement. On further investigation 

 he obtained a very simple explanation. Ferrata removed the salts 

 from his sera by dialyzing for twenty-four hours against distilled 

 water. In this process, of course, there is a precipitation of the 

 globulins while the water-soluble albumins remain in solution. The 

 former may be redissolved in normal salt solution and the latter 

 rendered isotonic by the addition of calculated amounts of concen- 

 trated salt. In this way the original serum components are divided 

 into two parts, neither of which, as Ferrata found, is alone capable 

 of producing hemolysis of sensitized cells. In order to obtain the 

 complementary action possessed by the original 

 serum it is necessary to combine the two. This 

 principle discovered by Ferrata is probably re- 

 sponsible also for the results obtained by Sachs 

 and Teruuchi, 50 who likewise noted the destruc- 

 tion of the complementary function in sera 

 diluted with distilled water, but attributed this, 

 in their publication, to the action of a comple^ 

 ment-destroying ferment, which is assumed to 

 be active in salt-free media only. 



In his first experiments Ferrata reported 

 that the precipitated globulin fraction was 

 thermostable, the thermolability of complement CONCEPTION OF COM- 

 being due entirely to the unprecipitated albu- Tm^A^I^^T 



min fraction. The work of Ferrata was soon SUGGESTED BY 



continued, however, by a number of other work- BRAND. 

 ers, who confirmed the essential fact of the par- 

 tition of the complement but modified and considerably extended the 

 original observations. Brand 51 found that both fractions were equally 

 thermolabile, and that the globulin sediment, after being redissolved 

 in salt solution, could not be preserved in an active condition for more 

 than a few hours. Preserved in distilled water or as sediment, it 

 may retain its activity for several days, but dissolved in salt solution 

 it becomes inactive within 3 to 4 hours, at room temperature. 

 Michaelis and Skwirsky 52 have since shown that the globulin frac- 

 tion, thermolabile when free, is unaffected by a temperature of 56 

 C. after it has become attached to sensitized cells. Brand further 

 studied the relationship of the two fractions to the sensitized cells 

 and found that the globulin fraction may attach directly to such 

 antigen-antibody complexes, but that the albumin fraction cannot be 

 bound in this way unless the globulin fraction has been previously 

 attached. For this reason he has referred to the former as the "end- 



50 Sachs and Teruuchi. Berl kl Woch., 1907, Nos. 16, 17, and 19. 



51 Brand. Berl. kl. Woch., 1907, No. 34. 



52 Michaelis and Skwirsky. ZeitscTir. f. Imm., Vol. 4, 1910. 



