1887 .] Professor Hay craft’s Abstract of Experiments. 421 
walls destroy the ferment in any way, I performed the following 
experiment : — 
Dilute blood ferment was injected and reinjected several times 
into the blood-vessels of a dog, previously freed from blood. The 
injected solution was as powerful in causing the coagulation of 
hydrocele fluid as a similar solution which had not been passed 
through the vessels. 
It is probable, therefore, that any injected ferment is destroyed 
within special organs or eliminated from the system. This would 
of course be a priori most probable. One is driven to conclude, 
therefore, that in the course of the ordinary circulation (whatever 
may take place in glandular structures) corpuscles do not break 
down, nor is free ferment present in the plasma. 
It is stated, however, by many to be present. 
Believing that this assumption is due to want of care in mani- 
pulation, I repeated well-known experiments, adopting special pre- 
cautions. 
Previous experimenters had obtained blood either from a cut 
vessel or from one fitted with a glass cannula. The blood must, 
therefore, have come in contact for a moment — a sufficient time 
to produce ferment — with the cut surface of the vessel or with the 
cannula. The blood was then received into a vessel containing a 
saturated solution of sulphate of magnesia. After filtration, the 
plasma was found to possess the power of clotting, on dilution. 
I repeated this experiment, mixing the magnesium sulphate 
solution with the blood while the latter teas still within a blood- 
vessel (an excised vein). After filtration, the diluted and dialysed 
plasma did not coagulate. 
I am inclined then to believe that blood corpuscles do not break 
down in the blood-vessels, or that if they do they do not set free 
any ferment. This latter is not present in circulating blood, which 
only fends to coagulate when it is brought in contact with solid 
matter. 
The exact way in which this solid matter acts, I hope to discuss 
in a subsequent paper. 
