223 ARTERY, PATHOLOGICAL CONDITIONS OF. 



maincd upon the wheel, the artery, divided in been fairly divided, or only notched, or punc- 



the subsequent amputation more than two tured ; to the wound being so large and patu- 



inches above the wound, did not pour out one lous as freely to permit the escape of all the 



drop of blood. In others, still, the cellular blood externally, or so small or oblique that 



sheath of the artery has been seen injected the fluid, though withdrawn from the circula- 



w'ith blood in a state of coagulation, the pres- tion, is still retained within the limb. There is 



sure of which on its orifice seemed to be still another condition of wounded artery in 



sufficient to prevent bleeding. which the blood that escapes from it is poured 



We are told that the observation made by into an adjacent vein, and continues to circulate, 



Amussat,* that in gun-shot wounds where all though not in its proper vessel. However, 



the parts were lacerated, the extremities of these latter cases are usually considered and 



even the larger vessels did not bleed, suggested described as forms of aneurism, and will, 



to him the application of the phenomenon therefore, not be noticed until there is an op- 



to practical surgery, and led to the practice portunity of comparing the different species of 



of the torsion of arteries. This operation con- that disease one with another, 



sists in laying bare a portion of the divided When a large artery is divided in an open 



artery, and carefully detaching it from the sur- wound, it may happen that the patient dies 



rounding cellular membrane until its own eel- almost instantaneously, not from the absolute 



lular tunic is distinctly to be seen ; it is then quantity of blood lost, but from its being with- 



seized with a forceps, not unlike the common drawn too suddenly from the circulation, just 



artery- forceps of Bell, and twisted on its axis as syncope is often produced by the rapid 



until the extremity engaged between the blades abstraction of blood in the common operation 



is completely detached by the torsion. This of phlebotomy. However, this is not uniformly 



forms something like a knot or knuckle at the the case, and experience has proved that vessels 



end of the vessel, which mechanically blocks of such size and importance as the carotid and 



it up ; a coagulum is formed within, and the femoral arteries may be divided, and yet suffi- 



remainder of the process is said nearly to re- cient time allowed for the successful interposi- 



semble that which succeeds the application of tion of art. Mr. Guthrie states, that when the 



a ligature. Not having practised torsion on femoral artery is cut across in the upper part of 



a vessel of any considerable size in the human the thigh, the patient does not always bleed 



subject, nor had an opportunity of examining to death, although frequently lost; while if the 



after death a case thus treated, I am unable to division takes place in the middle or lower half 



comprehend, with sufficient precision, the exact of the thigh, the bleeding will probably cease 



process that is established. In experimenting of itself. When/ however, an artery of still 



on the femoral arteries of dogs, I have always smaller size is divided, the powers of nature 



found that the immediate obstacle to the flow are almost always competent to restrain the 



of blood was a coagulum situated at the orifice, haemorrhage, and consequently it is from an 



and apparently entangled in the lacerated eel- examination of vessels of this class under such 



lular coat; but for the reasons already men- circumstances that a knowledge can be ob- 



tioned, little confidence can be placed in such tained of the nature and extent of these 



investigations. powers. 



Hitherto we have been considering those When a vessel of moderate size is divided, 

 wounds of arteries, which, however important the blood is poured forth in jerks from its 

 in other respects, are not attended by hsemor- open mouth in a large and full stream ; soon, 

 rhage, and although ignorant of the operations of however, this stream is seen to become dimi- 

 nature in effecting this result, it is of the less con- nished in size, and most probably it ceases to 

 sequence, inasmuch as it is not likely we shall flow per saltum. If the patient faints, the 

 attempt to imitate them, or entrust a large- bleeding perhaps ceases altogether, nor will it 

 sized vessel to torsion alone. The wounds of be renewed unless accident or indiscretion gives 

 arteries, accompanied by loss of blood, present to the blood an impetus sufficient to overcome 

 themselves under very different circumstances ; the obstacle that opposes its exit, whatever that 

 there is always anxiety, agitation, and dismay on may be. When the artery is divided, its middle 

 the part of the sufferer, and it may be that coat retracts immediately that its natural state 

 promptness and decision in the practitioner of tension is removed, withdrawing with it the 

 shall be required to preserve life. In any of lining membrane, but leaving the cellular, to 

 these awful situations, coolness and self-pos- which it is but loosely attached, hanging out 

 session can alone ensure a freedom from em- beyond it. It contracts, too, in diameter, as is 

 barrassment, and these qualities cannot be ex- evidenced by the diminished stream of blood, 

 pected in any ind ividual who has neglected to The power by which this contraction and re- 

 make himself acquainted with the nature of traction are performed is a vital property inhe- 

 the mischief that has occurred, and the means rent in the artery itself; it has been called 

 "by which it may be remedied. muscularity, and endless arguments have thus 



The phenomena attendant on arterial hse- been raised about a name, as if no tissue in the 



morrhage occasioned by incised and punctured body but muscle could be capable of contrac- 



wounds exhibit remarkable varieties, according tion. But it operates in a manner very different 



to the size, and of course to the structure of from the rapid and decided contraction of muscle ; 



the vessel ; to the circumstance of its having it is slow, gradual, and continued, and, there- 

 fore, is longer in bringing the large vessel into 



* Dictionairc de Chirurgic de Rust, torn. ii. a state favourable for the suppression of hsemor- 



