458 
COAGULATION OF THE BLOOD. 
the vessels ; and though it took longer to coagulate when let 
out from therm viz., five minutes, it did so as fully as before. 
The muscular irritability, as tested by a powerful galvanic 
battery, had been found, on the previous evening, to be 
entirely lost. I next obtained four other feet, with the veins 
turgid with blood, by applying bandages firmly to the limbs 
below the joints where the butcher removes them, and am- 
putating above the constricting band, after the sheep had 
been killed in the usual manner, by the knife. I examined 
veins in these limbs, day after day, till all the vessels were, 
exhausted, and found at the end of the sixth day, after their 
severance from all connexion with the vascular and nervous 
centres, that the blood from a deep vein was still perfectly 
fluid, and coagulated when shed, though the time occupied 
by the process was now half an hour — the length of the 
period having gradually increased, from day to day, since 
the time of the amputation. The feet, in the meantime, con- 
tinued perfectly sweet, the coldness of the weather at the 
time being very favorable for the experiments. Some blood 
from a subcutaneous vein of the same foot, where decom- 
position might be expected to occur somewhat earlier, con- 
tained, at the same period (the end of the sixth day), some 
minute portions of coagulum. The fluid part of this blood 
remained liquid for an hour, but then coagulated well. 
Hence it was evident that so long as the tissues retained 
their freshness, the blood within the vessels was kept in a 
state of fluidity by some agency utterly inexplicable by the 
ammonia theory. I also found that the same thing occurs 
in a cat. In one such animal, killed under chloroform, by a 
knife passed into the great vessels of the neck, the blood in 
the veins of the extremities remained perfectly fluid after 
forty-eight hours, and coagulated when shed. In* another 
cat, killed by asphyxia, the same was the case as regards the 
posterior extremities ; but the veins of the fore legs contained 
particles of coagulum, like the subcutaneous vessel of the 
sheep’s foot. This difference I am inclined to attribute to 
the fact, that the animal made violent and protracted exer- 
tion with the fore legs during the death struggle, thus 
exhausting their vital energies more than those of the other 
limbs. After four days, however, the blood in the hind legs, 
though still fluid, with the exception of very minute particles 
of coagulum, had lost its power of coagulation. This in- 
creasing slowness and final absence of coagulation in blood 
long kept within the vessels, is curious, and must, I imagine, 
depend upon some gradual change in the properties of the 
fibrine. 
( To be continued.) 
