1. The high value in respect to complement-binding exhibited by blood sera from syphilitics and spinal fluids from general paralytics is associated with an excessively high content of globulin, but there does not exist a direct quantitative relation between the two. Cases of secondary syphilis which have been under prolonged and proper medication do not exhibit the globulin increase and usually fail to give the Wassermann reaction. The active substances entering into the Wassermann reaction are precipitable with the globulin and chiefly with the euglobulin fraction of the fluids.
2. Temperatures of 70° to 76° C. destroy the active substances. Exposed to sunlight the active substances deteriorate slowly. A photodynamic substance such as eosin, under the direct influence of the sun, brings about their complete and rapid destruction. This effect does not occur in the dark. The active substances are subject to tryptic and peptic digestion and are destroyed by weak acids and alkalies.
3. The active substances in the blood sera and spinal fluids cannot be separated from them or from the globulin precipitate by alcohol.
4. There are contained in the alcoholic extracts of normal and syphilitic blood and organs certain acetone-soluble lipoids which possess high antigenic values for the Wasserman reaction. Cholesterin is inactive and the bile salts less active than the lipoidal bodies.
5. Sodium cholate is about as active as sodium taurocholate and glycocholate, but neurin and cholin are inactive.