serum of carcinomatous subjects, or of individuals with salpingitis, tuberculosis, and the like. Carcinoma is correctly prepared if it is not attacked by the serum of pregnant individuals.
Above all, the organ should be tested by means of cases which contain ferments acting against the components of the red blood corpuscles. Cases of blood effusion are excellent testing agents for the absence of blood in the prepared organ. Or disharmonious blood—in this case human blood—is injected into an animal, and its serum is tested against coagulated red blood corpuscles and the organ to be employed.
In conducting these experiments we must be able, with absolute certainty, to prevent the decomposition of all proteins other than those belonging to the actual organ itself. It is clear that serum, which contains a defensive ferment against the components of the form-elements of the blood, will decompose every organ containing blood—that is, it will split up, not the proteins of the organ, but the components of the blood within the organ. The importance of a clear recognition of this circumstance may be gathered from the fact that serum of normal horses and cattle decomposed red blood corpuscles in about 40 per cent. of cases. Further, it was found that serum taken from animals that exhibited hæmatoma produced decomposition with every kind of organ containing
