608 A MANUAL OF BACTERIOLOGY 



and Briick made use of a saline extract of an organ rich 

 in spirochaetes, viz., the liver of a syphilitic fetus, assum- 

 ing that in this way a specific antigen was obtained* As 

 a matter of fact, however, the Wassermann reaction, as 

 ordinarily performed, is not a specific antigen reaction, for 

 various alcohol-soluble and non-specific substances may be 

 used as antigen. Moreover, the nature of the substances 

 which act as amboceptor and together with antigen fix 

 the complement is uncertain ; some regard them as 

 globulins, others as lipoids, and while Wassermann con- 

 sidered them to be specific anti-bodies, others believe 

 them to be derived from a peculiar degeneration or break- 

 ing down of the tissues in syphilis. Again, the reaction 

 is not confined to syphilis : it may also be obtained (with 

 the antigen employed for syphilis) in malaria (p. 647), 

 yaws (p. 604), trypanosomiasis, Leishmaniasis, and leprosy 

 (p. 406). With a very sensitive antigen, scarlatina gives a 

 positive reaction during the first few days of illness. Of 

 the value of the Wassermann reaction as a means of 

 diagnosis there is now no question, it is widely employed 

 and forms a part of the present scheme for the control of 

 venereal disease in this country. 



The Wassermann reaction is a quantitative one, and 

 as the amount of the amboceptor-like bodies which fix 

 complement will vary from nil at the time of infection 

 up to a considerable amount when the disease is fully 

 developed, and vice versa during the period of treatment 

 and cure, border-line reactions will at times occur. That 

 is, while some departure from the normal is present, this 

 is not sufficiently marked to form a basis for a definite 

 diagnosis except in combination with the history and with 

 the clinical aspect of the case. It may, however, be con- 

 fidently stated that a well-marked positive Wassermann 

 reaction, obtained with the full technique, justifies a 

 definite diagnosis of syphilitic infection, provided that 



