The action of salvarsan on the clinical manifestations of syphilis is well understood at the present time. Its temporary effect on the Wassermann reaction is also fairly well known. To judge, however, of its ultimate effect on the disease either from a clinical or serologic standpoint will be possible only after many years have elapsed. It will therefore be seen that at the present time a serologic comparison of mercury and salvarsan must of necessity be unsatisfactory.
In attempting to collect statistics of various observers on the serologic action of the two remedies, we are confronted with very great difficulties. In the case of mercury the figures vary greatly according to the thoroughness of treatment, the preparation and administration of the drug and the stage of the disease at which the remedy is given. Indeed, there is even now no absolute agreement as to the very'best method of using mercury.
FOX H. THE RELATIVE VALUE OF MERCURY AND SALVARSAN FROM A SEROLOGIC POINT OF VIEW. JAMA. 1912;LIX(14):1243–1248. doi:10.1001/jama.1912.04270100013005