These experiments show:
1. That the surface tension of normal blood serum is considerably lowered by standing undisturbed for a period of 1 hour (time-drop).
2. That the greatest time-drop recorded is with serum diluted approximately 10,000 times in fresh serum, and 50,000 times in heated serum.
3. That immune serum is not affected in the same manner by heat as is normal serum. Syphilitic serum and anti-sheep cell rabbit serum behave similarly in this respect.
4. That serum albumin is much more readily soluble in alkaline buffer solutions than globulin is, and that globulin from normal serum ionizes more than that from syphilitic serum.
Further investigations are being made in an effort to determine why the proteins aggregate or dissociate under the influence of the factors under consideration.