is error can be
avoided by raising the edge of the periosteum from the bone, with the
gloved finger. On combined auscultation and percussion a peculiar
"hollow-cask" sound may be detected in some cases of fissured fracture
of the vault.

Fissured fractures as such call for no _treatment_. When compound, the
wound must be disinfected; and intra-cranial complications, such as
meningeal haemorrhage, laceration of the brain, or infection, are to be
treated on the lines already described.

#Punctured fractures# are of necessity compound, and on account of the
risks of infection are to be looked upon as serious injuries. They
result from the localised impact of a sharp, and usually infected
object the point of which is not infrequently left either in the bone
or inside the skull. Fragments of bone are often driven into the
brain, and short fissures frequently pass in various directions from
the central aperture.

_Diagnosis._--When the instrument impinges on the head obliquely,
after piercing the scalp it may pass for some distance under it before
perforating the skull, so that on its withdrawal a valvular wound is
left, and at first sight it appears that only the scalp is involved.
Sometimes a foreign body left in the gap so fills it up that it is
difficult to detect the fracture with a probe or even with the finger.
In all doubtful cases the scalp wound should be sufficiently enlarged
to exclude such errors. We have known of a case of a man who died of
meningitis resulting from a punctured fracture of the vault caused by
the spoke of an umbrella, the fracture having escaped recognition
until the meningeal symptoms developed.

_Treatment._--The scalp wound must be purified, being opened up as far
as necessary for this purpose. The infected portion of bone should be
removed to render possible the purification of the membranes and
brain, and to permit of drainage.

#Depressed and Comminuted Fractures.#--As these varieties almost
always occur in combination, they are best considered together. The
terms "indentation fracture," "gutter fracture," "pond fracture," have
been applied to different forms of depressed fracture, according to
the degree of damage to the bone and the disposition of the fragments
(Figs. 188, 189, 190). These fractures may be simple or compound.

[Illustration: FIG. 188.--Depressed Fracture of Frontal
Bones--involving the air sinus on both sides--with a fissured fracture
radiating from it.

(From