METHODS FOR CONDUCTING THE SYPHILIS REACTION 457 



aqueous extracts of syphilitic liver as antigen. It is true that this method 

 is not an exact quantitative reaction, and that it is probably less delicate 

 than some of the modified methods, but its advantages are that it is 

 easy of manipulation, is readily learned, and is especially recommended 

 for persons who perform these tests at irregular intervals, as false positive 

 reactions are less likely to occur than when the more delicate methods 

 are used. 



Second Method ; the Wassermann Reaction with Multiple Antigens. 

 In this method the technic is essentially the same as in the first 

 method, except that three different antigens are used instead of one, 

 namely, cholesterinized extract of normal heart, alcoholic extract of 

 syphilitic liver, and acetone-insoluble lipoids. This method has three 

 advantages: (1) It permits the use of a cholesterinized extract under 

 conditions where any tendency to non-specific fixation is to be controlled ; 

 (2) an antigen may at any time suddenly become anticomplementary 

 and yield false results, whereas by this method the source of error is 

 detected and may be avoided, since it is not dependent upon any one 

 extract; (3) an extensive study of the comparative values of antigens 

 has led to the distinct impression that the lipodophilic antibody in 

 different syphilitic serums frequently shows a special affinity for the 

 lipoids in a certain plain antigen more than it does for those in 

 another antigen; in fact, I have not infrequently found that, with 

 weakly positive serums, if one antigen had been emploj^ed, a false 

 negative report would have been rendered, the true reaction being 

 given by the other two antigens. These results could not be as- 

 cribed to faulty antigen, for with other weakly positive serums the ex- 

 tract would be found to react satisfactorily. 



As previously mentioned, cholesterinized alcoholic extracts are 

 very sensitive, so that from this standpoint additional antigens would 

 appear to be superfluous. This very property, however, in my 

 opinion, renders it advisable to control them with less sensitive ex- 

 tracts. In this way all the advantages of a very sensitive antigen 

 may be secured, and the disadvantages avoided until more extended 

 use demonstrates whether or not it is entirely safe to use these extracts 

 alone. 



With strongly reacting serums all antigens possess equal antigenic 

 power. With the serums of long-standing or treated cases of syphilis 

 the cholesterinized extracts may react strongly positive, whereas with 

 the aqueous and the alcoholic extracts the reactions are weakly 

 positive, or negative with one and positive with the other. In cases 

 of syphilis that have received considerable treatment the reaction 



