Stimulated by Whipple's1 study of the blood-plasma of purpura, and also by the availability of a few patients with purpuric manifestations, we undertook the study, from the point of view of clinical adaptability, of the methods of determining the coagulation properties of the blood-plasma of purpura. We found it necessary, however, in connection with this work, to study in detail the general principles of coagulation, and we therefore present our results under the two general heads of (1) "Experimental" and (2) "Clinical Studies."
In the course of our early work we were impressed with the ease of preparing from dog's blood-cells a solution with great thromboplastic activity and comparatively so free from prothrombin or thrombin as to be available as a source of thromboplastin in clinical studies. This solution was prepared as follows: From a normal dog that had fasted twenty-four hours, blood from the jugular
AUSTIN JH, PEPPER OHP. EXPERIMENTAL OBSERVATIONS ON THE COAGULATION OF OXALATED PLASMA, WITH A STUDY OF SOME CASES OF PURPURA. Arch Intern Med (Chic). 1913;XI(3):305-313. doi:10.1001/archinte.1913.00060270059005