vessel
short of perforation, but severe enough to so lower the vitality that
local gangrene of the wall occurs. In such instances haemorrhage most
usually occurred on the tenth to the fourteenth day, but occasionally
still later. In one instance of ligature of the anterior tibial artery
for such haemorrhage three-quarters of the whole lumen of the vessel had
been devitalised. The resemblance of some cases of secondary haemorrhage
of this class to those occasionally observed after amputation, and due
to accidental non-perforative injury of the artery at the time of
operation above the point of ligature, was very striking.

In other cases secondary haemorrhage was the result of perforation of the
vessel by a sharp spicule of bone, but in the large majority sepsis and
suppuration were the cause. Naturally therefore the accident was
commoner in the more severe kinds of wound, and in those caused by
_large_ bullets or fragments of shell. The symptoms in nearly all cases
were the classical ones of repeated small haemorrhages followed by a
sudden copious gush.

The forms of secondary haemorrhage, however, which afforded most interest
were the interstitial and the internal, mainly on account of the scope
they allowed for diagnosis.

Characteristic examples of internal secondary haemorrhage are furnished
by cases of chest injury accompanied by haemothorax and fully dealt with
under that heading (Chapter X.). Cases of interstitial secondary
haemorrhage are also described under the heading of traumatic aneurism
and abdominal injuries (No. 194, p. 445). It therefore suffices here
merely to remark on the diagnostic difficulties the condition gave rise
to. These mainly depended upon the elevation of general bodily
temperature by which the haemorrhage was often accompanied. Further
evidence of the condition was furnished by the development of local
swellings, or physical signs indicative of the collection of fluid in a
serous cavity. These signs developed rapidly, and the rise of
temperature was sudden and decided enough to suggest commencing
suppuration. In several cases incisions were made under the supposition
that this had already occurred.

The fever accompanying blood effusions was generally a somewhat special
feature in the wounds of the campaign. At first bearing in mind that in
every case a track, even if closed, led from the surface to the effused
blood, one was disposed to suspect an infection of the clot of a
somewha