ding we tie the vessel C, Plate 17, still the vessel F will
continue to bleed, in consequence of its communication with the vessel
E, Plate 18, by the branch 1, Plate 18, and other branches above
mentioned. If E, Plate 18, bleeds, a ligature applied to the vessel A,
Plate 18, will not stop the flow of blood, because of the fact that E
anastomoses with G, by the branch I and other branches, as seen in
Plates 17 and 19.

Any considerable haemorrhage, therefore, which may be caused by a wound
of the superficial or deep palmar arches, or their branches, and which
we are unable to arrest by compression, applied directly to the patent
orifices of the vessel, will in general require that a ligature be
applied to both the radial and ulnar arteries at the wrist; and it
occasionally happens that even this proceeding will not stop the flow of
blood, for the interosseous arteries, which also communicate with the
vessels of the hand, may still maintain the current of circulation
through them. These interosseous arteries being branches of the ulnar
artery, and being given off from the vessel at the bend of the elbow, if
the bleeding be still kept up from the vessel wounded in the hand, after
the ligature of the ulnar and radial arteries is accomplished, are in
all probability the channels of communication, and in this case the
brachial artery must be tied. A consideration of the above mentioned
facts, proper to the normal distribution of the vessels of the upper
extremity, will explain to the practitioner the cause of the difficulty
which occasionally presents itself, as to the arrest of haemorrhage from
the vessels of the hand. In addition to these facts he will do well to
remember some other arrangements of these vessels, which are liable to
occur; and upon these I shall offer a few observations.

While I view the normal disposition of the arteries of the arm as a
whole, (and this view of the whole great fact is no doubt necessary, if
we would take within the span and compass of the reason, all the lesser
facts of which the whole is inclusive,) I find that as one main vessel
(the brachial) divides into three lesser branches, (the ulnar, radial
and interosseous,) so, therefore, when either of these three supplies
the haemorrhage, and any difficulty arises preventing our having access
at once to the open orifices of the wounded vessel, we can command the
flow of blood by applying a ligature to the main trunk--the brachial. If
this m