THERAPEUTIC IMMUNIZATION IN MAN 513 



formed in syphilis. As matters have developed, however, this point 

 of view can no longer be maintained. It was soon discovered that 

 the antigen used for these reactions by Wassermann and his associates 

 derived its "fixing" constituent not from the body substances of the 

 treponemata contained in the syphilitic organs, but from certain 

 tissue extractives chiefly of lipoidal nature which could be obtained 

 readily from normal as well as syphilitic tissues. Although Bruck 157 

 and others who have occupied themselves with the theoretical basis 

 of the Wassermann reaction, still maintain that a specific antibody 

 may be incidentally involved, they admit that this is the less im- 

 portant factor in the reaction which depends chiefly upon the ex- 

 istence of lipotropic substances which appear in the course of the 

 disease as metabolic products either of the body or possibly of the 

 treponemata. This is a subject which we will deal with in extenso 

 in another paper. It is sufficient for our present purposes to point 

 out that, although to a slight extent specific antibodies may play a 

 part in the Wassermann reaction, this is certainly not the chief 

 element or even a very important factor involved. The truth of this 

 conception has been further confirmed by the work of Noguchi, 158 

 of Craig and Nichols, 159 of Kolmer, 160 and ourselves, in which it 

 has been found that antigens made with pure cultures of treponemata 

 produced a complement fixation with syphilitic sera to a very limited 

 extent only, and in our work in which we have been able to duplicate 

 the Wassermann reaction in a large series of antigens made from the 

 treponema cultures, we have found that similar results could be 

 obtained with cultures of colon and typhoid bacilli identically pre- 

 pared, the fixing power to a large degree depending upon the lipoidal 

 constituents of the bacteria. Whatever the ultimate explanation of 

 the Wassermann reaction may turn out to be (and this is a subject 

 which it would not be profitable to discuss at length at this place), it 

 cannot be maintained that as it exists at present, it can be interpreted 

 as demonstrating the existence of true circulating antibodies, analo- 

 gous to those found in bacterial diseases in the blood of syphilitic 

 patients. 



Early in the history of such investigations, Fornet, 161 with his 

 collaborators Schereschewsky, Eisenzimmer, and Rosenfeld, 162 found 

 that when the sera of syphilitics were mixed with clear extracts of 

 syphilitic livers similar to those used in the Wassermann reactions, 

 precipitates formed which were not seen in similar experiments done 



157 Bruck. Imm. bei Sypn. in Kolle u. Wassermann Handb. d. Pathog. 

 Mikroorg., vii, 1045 et seq. 



158 Noguchi, H. Jour. Exper. Med., 1911, xvi, 99. 



159 Craig, C. F., and Nichols, H. J. Jour. Exper. Med., 1912, xvi, 336. 



160 Kolmer, J. A. Jour. Exper. Med., 1913, xviii, 18. 



lei Fornet. XIV Internal. Kongress f. Hyg. und Derm., Sept. 1, 1907. 

 162 Fornet, Schereschewsky, Eisenzimmer and Rosenfeld. Deutsch. med. 

 Wcbnschr., 1907, No. 41. 



