Variations in the clotting power of the blood are encountered in diverse manifestations of practical medicine. Not infrequently they are occasion for uncertainty and annoyance, particularly when conditions arise in which an inhibition of coagulation accompanies some hemorrhagic diathesis. Until the physiologic factors concerned in the coagulation of the blood are more clearly understood, it is almost unwarranted to expect any real progress in the management of the often serious situations created by certain types of uncontrollable hemorrhage. Empiric experience has served as a guide in the past, and the remedial procedures instituted have as a rule been local and palliative rather than fundamental and permanent in character.
The coagulation of the blood has formed the subject of intensive study on the part of physiologists and biochemists for decades. Even the most recent literature in this field abounds in many contradictory statements, irreconcilable observations and obscure points. It calls for