426 ' IMMUNOLOGY 



6 and 7. These controls were to demonstrate that aqueous ex- 

 tracts of syphilitic and normal liver respectively are not anti- 

 eomplementar3\ 



8, 9 and 10. These controls were to ascertain whether the pa- 

 tient's serum, known positive and negative sera were anticom- 

 plementary. 



In addition to these there was included a control on the hemo- 

 lytic system and also on alcoholic extracts of both syphilitic and 

 normal tissues when these were employed. 



Wassermann 's first paper appeared in 1906 and contained re- 

 sults that were encouraging but far from satisfactory. Wasser- 

 mann, Neisser, Bruck and Schucht (1906) and Wassermann and 

 Plant (1906) made additional reports upon the new method of 

 diagnosis of syphilis. They concluded that it was a specific com- 

 plement fixation test for spirochetal antibodies in the patient's 

 serum and that it possessed diagno.stic value. 



Importance of Citron's Work.— Citron (1907, 1908, 1909, 

 1912) was apparently one of the first to confirm their results and to 

 make extensive use of the test as an aid in the diagnosis of syph- 

 ilis in man. 



First Stage of the Development of the Wassermann Reac- 

 tion. — Kolmer (1922) speaks of three stages in the development of 

 the Wassermann reaction. The first was the one just discussed in 

 which the reaction was considered as due to the fixation of com- 

 plement by spirochetes that had been sensitized by specific anti- 

 bodies prasent in the patient's blood serum. 



Second Stage Began With the Use of Alcoholic Extracts 

 OF Guinea Pig Heart. — The second stage began in 1906, 1907, 

 when Landsteiner and Stankovic (1906), Marie and Levaditi 

 (1907) and Landsteiner, Miiller and Potzl (1907) showed that 

 alcoholic extracts of normal guinea pig heart as well as syphilitic 

 tissues could l)e used successfully as an antigen in the complement 

 fixation test for syphilis. This led to extensive chemical studies 

 of these alcoholic extracts and to a realization that lipoids and not 

 spirochetes were sensitized by an antibody-like substance in the 

 serum of syphilitic patients and that this lipoid-antibody complex 

 was responsible for the fixation of complement in the Wassermann 

 test. H. Sachs and others attempted to introduce artificial antigens 

 with indifferent results except for the acetone-insoluble lipoid 



