Laboratory aids to the clinical diagnosis of syphilis have developed rapidly since the announcement by Schaudinn and Hoffman1 in 1905, of the Treponema pallidum as the probable causative agent. Prior to that time the rarely used Justus test (increase of hemoglobin after the administration of mercury) was the only laboratory procedure. A subject so vast and important can be approached from many sides, the more important being the technical, clinical and experimental. Therefore, it will be necessary to limit this paper to those of more general and practical use, and to avoid long technical descritptions; in other words, to present to the general practitioner the value and limitations of the various laboratory methods, rather than to dwell on the means of carrying them out.
This was the first method used generally for purpose of demonstrating the presence of the Treponetna pallidum. Many stains and mordants have been used.