FIXATION OF COMPLEMENT 139 



mann reaction has become positive, a proportionate 

 increase in treatment will be required to eradicate the 

 disease. In the tertiar}- stage it is impossible in some 

 cases to render the reaction negative. 



Under treatment the symptoms usually disappear 

 before the Wassermann reaction becomes negative, 

 though occasionally the opposite holds true; that is, 

 cases under treatment may present a negative reaction 

 although symptoms are still manifest. The reaction 

 may persist for some time after all symptoms have 

 disappeared, indicating that further treatment is 

 necessary. After being rendered negative by treat- 

 ment, the reaction may after a time again become 

 weakly positive, then gradually stronger, and finally be 

 followed by a reappearance of symptoms. It is not 

 yet possible to say when a negative reaction in a case 

 that has received treatment means that the patient is 

 cured of syphilis. If negative Wassermanns have 

 been obtained at intervals of three or four months over 

 a period of two years, during which the patient has 

 had no treatment and with no recurrence of symp- 

 toms, it is probably justifiable to regard the case as 

 cured. But it will require ten to twenty years' exper- 

 ience with the reaction to be positive that the so-called 

 parasyphilitic diseases or other late manifestations will 

 not develop even after such a series of negative tests. 



JNIuch closer readings of the reaction should be 



