sceral
arteries, as of the lungs, liver, or mesentery, were scarcely less rapid
in their results. In such cases the potential space offered by the
peritoneal or pleural cavities favours the ready escape of blood from
the wounded vessel, while the tendency of the blood effused into serous
cavities to rapid coagulation is notably slight. Beyond this the
comparative deficiency in direct support afforded by surrounding
structures to vessels running in the large body cavities is also an
important element in their behaviour when wounded.

These remarks receive support from the observation that few, if any,
patients survived an injury to the external iliac vessels within the
abdomen, while the remarkable instances of escape from fatal haemorrhage
from large vessels recorded below (cases 1-19) indicate that the mere
size of a wounded vessel is not to be regarded as the sole factor in
prognosis.

_Recurrent haemorrhage_ was occasionally met with both in the case of the
limb and trunk vessels. In the limbs it often necessitated ligature of
the artery. I saw several cases in the lower extremity where recurrent
haemorrhage on the second or third day was treated by ligature of the
femoral or popliteal artery, and it also occurred during the course of
development of one of the carotid aneurisms recounted below. On two
occasions I saw rapid death follow recurrent abdominal haemorrhage; in
one I was standing in a tent when a man who had been wounded the day
before suddenly exclaimed: 'Why, I am going to die after all.' The
appearance of the man was ghastly, and on examining the abdomen it was
found greatly distended, and with dulness in the flanks; the patient
expired a few minutes later. Another example of recurrent abdominal
haemorrhage is related in case 169, p. 432.

_Secondary haemorrhage._--In simple wounds of the soft parts by
_small-calibre bullets_ this was decidedly rare. In wounds complicated
by fractures of the bones, especially when they exhibited the so-called
'explosive' character, secondary haemorrhage was not uncommon, and this
not necessarily in conjunction with infection and suppuration.

In the chapter on fracture some remarks will be found on the
prolongation of healing often observed in the exit portion of the wound
track, which is explained by the well-known fact that, given an aseptic
condition of the wound, sloughs of tissue separate very slowly.
Secondary haemorrhage in these cases is due to lesions of the