APPENDIX A. 



THE WASSERMANN TEST FOR SYPHILIS. 



As has already been pointed out on page 69, 

 Wassermann applied the principle of the Bordet- 

 Gengou phenomenon to the detection of syphilis 

 antibodies in the serum and cerebrospinal fluid of 

 persons infected with syphilis. In the two years 

 which have elapsed since Wassermann's first pub- 

 lication, the reliability of this method of diagnos- 

 ing syphilis has been confirmed by a large number 

 of investigators, and it has already proven of con- 

 siderable value in several departments of medicine. 

 In response to numerous requests, the writer has 

 undertaken to give a clear description of the test, 

 together with a brief review of the results thus far 

 achieved by its use. 



When an animal is repeatedly injected with red 

 blood cells of another species, it reacts to such in- 

 jections by producing substances in its serum which 

 have the power to dissolve these foreign blood cells. 

 Examined by means of a test tube experiment, it 

 is found that the serum exerts this power only 

 while it is fresh. Serum several days old is unable 

 to dissolve the red cells. The fresh serum also 



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