gion of the shoulder.

In alcoholic or other debilitated patients, suppuration is liable to
ensue in bruised parts, infection taking place from cocci circulating in
the blood, or through the overlying skin.

_Terminations of Contusions._--The usual termination is a complete
return to the normal, some of the extravasated blood being organised,
but most of it being reabsorbed. During the process characteristic
alterations in the colour of the effused blood take place as a result of
changes in the blood pigment. In from twenty-four to forty-eight hours
the margins of the blue area become of a violet hue, and as time goes on
the discoloured area increases in size, and becomes successively green,
yellow, and lemon-coloured at its margins, the central part being the
last to change. The rate at which this play of colours proceeds is so
variable, and depends on so many circumstances, that no time-limits can
be laid down. During the disintegration of the effused blood the
adjacent lymph glands may become enlarged, and on dissection may be
found to be pigmented. Sometimes the blood persists as a collection of
fluid with a newly formed connective-tissue capsule, constituting a
_haematoma_ or _blood cyst_, more often met with in the scalp than in
other parts.

The impairment of the blood supply of the skin may lead to the formation
of _blisters_, or to _necrosis_. Death of skin is more liable to occur
in bleeders, and when the slough separates the blood-clot is exposed and
the reparative changes go on extremely slowly. _Suppuration_ may occur
and lead to the formation of an abscess as a result of direct infection
from the skin or through the circulation.

_Treatment._--If the patient is seen immediately after the accident,
elevation of the part, and firm pressure applied by means of a thick pad
of cotton wool and an elastic bandage, are useful in preventing effusion
of blood. Ice-bags and evaporating lotions are to be used with caution,
as they are liable to lower the vitality of the damaged tissues and lead
to necrosis of the skin.

When extravasation has already taken place, massage is the most speedy
and efficacious means of dispersing the effused blood. The part should
be massaged several times a day, unless the presence of blebs or
abrasions of the skin prevents this being done. When this is the case,
the use of antiseptic dressings is called for to prevent infection and
to promote healing, after which massage is employed