APPLICATION OF COMPLEMENT FIXATION 207 



value lies in the differentiation of smallpox from syphilis and from 

 chicken-pox (varicella). 



Whooping-Cough. With antigens made from the pertussis bacil- 

 lus of Bordet-Gengou the reaction appears to have considerable diag- 

 nostic value. 



Echinococcus Cyst. The antigen is obtained by filtering the cyst 

 fluid of .man or sheep and preserving with 0.5 per cent, phenol in a cool 

 place. Varying results have been reported, but the test appears to be 

 worthy of further investigation where material can be obtained for 

 its use. 



Malignant Tumors. Numerous attempts have been made to aid 

 in the diagnosis of malignant tumors by the complement-fixation test, 

 using antigens prepared from tumor material. The results have been 

 conflicting. Von Dungern has devised a test using, on empirical 

 grounds, an antigen prepared by making an acetone extract of normal 

 human red blood-cells. He has obtained fixation in as high as 90 per 

 cent, of known cases of malignant tumors. The test, however, has not 

 as yet been sufficiently widely applied to justify recommending it as 

 of clinical value. 



Sporotrichosis. Widal, Abrami, Joltrain and Weil have obtained 

 excellent results using as antigen the sporotrichum Beurmanni. Moore 

 and Davis have recently demonstrated fixation with a human serum in 

 the presence of Schenck-Hektoen, Beurmann and Davis strains of 

 the organism. This reaction, in addition to agglutination, is of distinct 

 diagnostic value. 



