434 
COAGULATION OF THE BLOOD. 
jugular vein of an ox. I wished to compare the condition 
of blood which had been simply poured into a tube with 
blood which had been introduced without any disturbance of 
its central parts. But in order to make the experiment a 
fair one, as it might be said that the blood poured from the 
vein had been more exposed to the air than that into wffiich 
the tube w T as slipped, I proceeded in the following way :—I 
obtained a long vein containing plenty of blood, and having 
first filled the second tube with the gutta-percha bottom by 
simply pouring blood into it from the vein, I cut off a portion 
of the vein which had been thus emptied, and having tied 
one end and everted the lining membrane of the other end, 
and having also everted the lining membrane of the orifice of 
the remainder of the vessel wffiich was full, I poured the 
blood from the full portion through the air into the empty 
part. In doing this I had difficulty in getting blood enough, 
and it passed through the air in slow drops, and that only 
when the vein w 7 as squeezed by my warm hand. At last, 
having introduced sufficient for the purpose, I slipt down 
the compound tube and bent its gutta-percha portion, and 
left both tubes for awffiile undisturbed. At the end of three 
hours and a half I found that the blood which had been 
simply poured in w 7 as a mass of clot, and fluid squeezed from 
it yielded no threads of fibrin, coagulation being complete. 
How long it had been so I do not know. I did not examine 
the other blood until seven hours and three quarters had 
expired, and then found that, just as in the cases where a 
simple glass tube w 7 as introduced, the clot was tubular, and 
the chief part of the blood was still fluid in its interior, the 
only difference being that in this case the clot formed a com¬ 
plete capsule, being continued over the gutta percha instead 
of being deficient below, as it was when the vein closed the 
end of the tube. Now, if w r e consider the tw r o parts of this 
comparative experiment, we see that the receptacles in wffiich 
the blood was ultimately contained were precisely similar in 
the two cases—viz., glass tubes closed below wdth gutta 
percha; and that the blood which w T as simply poured into 
the tube w 7 as much less exposed to the air than the other, and 
also was not subjected, like it, to elevation of temperature, a 
circumstance which promotes coagulation ; but yet this blood 
became completely coagulated in a comparatively short time, 
w hereas the other after a much longer time w 7 as coagulated 
only in a layer in contact w 7 ith the foreign solid. But in the 
latter case the blood had been so introduced as to avoid direct 
action of ordinary matter on any but the circumferential 
parts of it; whereas in the former, though poured quickly. 
