COAGULATION OF THE BLOOD. 
433 
proper management it might be possible to keep blood fluid 
in a vessel of ordinary solid matter lined with clot. But 
various attempts made with this object failed entirely, till I 
lately adopted the following expedient:—Having opened 
the distal end of an ox’s jugular vein containing blood and 
held in the vertical position, taking care to avoid contact of 
any of the blood w 7 ith the w T ounded edge of the vessel, I 
slipped steadily down into it a cylindrical tube of thin glass, 
somewhat smaller in diameter than the veins, open at both 
ends, and with the lower edge ground smooth in order that 
it might pass readily over the lining membrane, and so 
disturb the blood as little as possible by its introduction, and 
influence only the circumferential parts of its contents. 
The tube was then kept pressed down vertically upon the 
bottom of the vein by a weight, in a room as free as possible 
from vibration, and I found, on examining it at the end of 
twelve hours, that the clot was a tubular one, consisting of 
a crust about one eighth of an inch thick next the glass and 
the part exposed to the air, but containing in its interior 
fluid and rapidly coagulable blood. In another such experi¬ 
ment, continued for twenty-four hours, though the crust of 
clot was thicker, the central part still furnished coagulable 
blood. 
But it may perhaps be argued by those who say that the 
blood-vessels are active in maintaining fluidity that the small 
portion of the vein covering the end of the tube was acting 
upon the blood, w T hich certainly was fluid where in contact 
with it, the clot being in the form of a tube open at the lower 
end. To guard against such an objection I made the follow 7 - 
ing experiment :—I extended a tube like that above described 
by means of thin sheet gutta percha, contriving that the 
internal surface of the gutta percha should be perfectly con¬ 
tinuous w T ith that of the glass tube. The lower part of the 
gutta-percha tissue was strengthened by a ring of soft flexi¬ 
ble wire, such as is used by veterinary surgeons for sutures, 
and the w 7 ire w r as also extended upwards to the top of the 
glass so as to maintain the rigidity of the gutta-percha portion 
during its introduction into a vein, but at the same time, 
from its softness, permit the gutta-percha part to be bent at 
a right angle after it had been introduced, and so close the 
orifice of the glass tube w T ith ordinary solid matter. At the 
same time I performed a comparative experiment, to which I 
w 7 ould invite particular attention, although I am sorry at this 
late hour to occupy the attention of the society so long. I 
tied a thin piece of gutta-percha tissue over the lower end of 
a similar glass tube, and simply poured blood into it from the 
