while the knee is
kept extended; and by active movements--the patient flexing the limb at
the hip, the knee being maintained in the extended position. These
exercises, which may be preceded by massage, are carried out night and
morning, and should be practised systematically by those who are liable
to sciatica.

Benefit has followed the injection into the nerve itself, or into the
tissues surrounding it, of normal saline solution; from 70-100 c.c. are
injected at one time. If the pain recurs, the injection may require to
be repeated on many occasions at different points up and down the nerve.
Needling or acupuncture consists in piercing the nerve at intervals in
the buttock and thigh with long steel needles. Six or eight needles are
inserted and left in position for from fifteen to thirty minutes.

In obstinate and severe cases the nerve may be _forcibly stretched_.
This may be done bloodlessly by placing the patient on his back with the
hip flexed to a right angle, and then gradually extending the knee until
it is in a straight line with the thigh (Billroth). A general anaesthetic
is usually required. A more effectual method is to expose the nerve
through an incision at the fold of the buttock, and forcibly pull upon
it. This operation is most successful when the pain is due to the nerve
being involved in adhesions.

#Trigeminal Neuralgia.#--A severe form of epileptiform neuralgia occurs
in the branches of the fifth nerve, and is one of the most painful
affections to which human flesh is liable. So far as its pathology is
known, it is believed to be due to degenerative changes in the semilunar
(Gasserian) ganglion. It is met with in adults, is almost invariably
unilateral, and develops without apparent cause. The pain, which occurs
in paroxysms, is at first of moderate severity, but gradually becomes
agonising. In the early stages the paroxysms occur at wide intervals,
but later they recur with such frequency as to be almost continuous.
They are usually excited by some trivial cause, such as moving the jaws
in eating or speaking, touching the face as in washing, or exposure to a
draught of cold air. Between the paroxysms the patient is free from
pain, but is in constant terror of its return, and the face wears an
expression of extreme suffering and anxiety. When the paroxysm is
accompanied by twitching of the facial muscles, it is called _spasmodic
tic_.

The skin of the affected area may be glazed and red, or may