MR. COSTELLO ON THE TORSION OF ARTERIES. 
209 
proportionate to the shortening which takes place by the effect 
of the twisting, so that it will be scarcely visible on the surface 
of the stump. It is of the utmost importance to seize the artery 
perfectly, and to make the stated number of twists, as otherwise 
the security against the danger of consecutive hemorrhage will 
not be so perfect. . , 
It has been already stated, that, when we apply a ligature, the 
internal tunics of the artery are divided. In the torsion, these 
tunics are also divided ; but in comparing one with the other, 
there will be this difference,-that in the case of the hgatuie, 
the internal tunics, though detached from the cellular coat, re¬ 
main, nevertheless, close to it, so that there exists but very little 
space between them; but in the torsion these tunics ascend, and 
take a position in the middle of the clot, to the rapid formation 
of which they contribute, and the clot itself extends to the next 
collateral: a space exists between the knot and the internal tu¬ 
nics in which the cellular coat inflames, when plastic lymph is 
thrown out, and the first obturation of the end of the vessel is 
effected. The same process of exudation takes place fiom the 
internal tunics higher up, and the clot thus becomes adherent to 
the circumference of the arterial tubes, and thus also the obli¬ 
teration of the vessel is rendered doubly secure. 
Experiment 1.—M. Delcroix, M. Amussat s assistant, laid bare 
the femoral artery of a middle-sized dog, w hen I applied two pairs 
of forceps on the vessel, which I divided in the interval, an , 
according to the process described, twisted the upper end eight 
times, and replaced it. There resulted no hemorrhage. I then 
twisted the lower one, but not being au jait. of the manoeuvre, 
which I should observe requires tact and practice, it was lrnpei- 
fecllv effected. Consecutive hemorrhage came from the lower 
vessel, which I sought, and, again seizing it and treeing it from 
its connexions, I twisted it eight times, when the hemorrhage 
instantly ceased. . ^ A 
Experiment 2.—I laid bare the femoral artery of a laige do 0 . 
The vessel was of large caliber: I proceeded as before, and no 
hemorrhage took place. ., . j t 
Experiment 3.—The carotid of a mastiff was laid bare, and 1 
practised the torsion as before. The size of the vessel was con¬ 
siderable. I twisted the vessel on the side of the capillaries eight 
times, and on the side of the heart until the rupture of the por¬ 
tion held in the forceps was effected. No hemorrhage ensued 
from either. , , . . j i 
Experiment 4.-The femoral of a large dog was laid bare, and 
was twisted in. the usual way on one side, until rupture was ef¬ 
fected, and on the other until a knot only was formed. 1 now, 
