From a clinical standpoint the Wassermann reaction is generally looked upon as a specific test for syphilis. This statement is made with a clear understanding that in some few exceptions, false or “pseudo-positive” reactions may occur, but a test which will give positive results in some 90 per cent to 98 per cent of cases, from a clinical standpoint, may be looked upon as specific.
Larkin, Levy and Fordyce (1) have found a positive reaction in practically 100 per cent of cases of florid syphilis, and in 94 per cent of active tertiary. Craig in 90 per cent primary cases, in 96 per cent secondary and 87.4 per cent tertiary cases obtained a positive Wassermann reaction. These figures merely show the comparatively slight variations that do occur with different workers and with cases in different stages of the disease. It is not within the scope of this paper however, to discuss all conditions affecting the Wassermann reaction on the blood.