axis._--The toes and feet of old people, the condition of whose
circulation predisposes them to gangrene, should be protected from
slight injuries such as may be received while paring nails, cutting
corns, or wearing ill-fitting boots. The patient should also be warned
of the risk of exposure to cold, the use of hot-bottles, and of placing
the feet near a fire. Attempts have been made to improve the peripheral
circulation by establishing an anastomosis between the main artery of a
limb and its companion vein, so that arterial blood may reach the
peripheral capillaries--reversal of the circulation--but the clinical
results have proved disappointing. (See _Op. Surg._, p. 29.)

_Treatment._--When there is evidence that gangrene has occurred, the
first indication is to prevent infection by purifying the part, and
after careful drying to wrap it in a thick layer of absorbent and
antiseptic wool, retained in place by a loosely applied bandage. A
slight degree of elevation of the limb is an advantage, but it must not
be sufficient to diminish the amount of blood entering the part.
Hot-bottles are to be used with the utmost caution. As absolute dryness
is essential, ointments or other greasy dressings are to be avoided, as
they tend to prevent evaporation from the skin. Opium should be given
freely to alleviate pain. Stimulation is to be avoided, and the patient
should be carefully dieted.

When the gangrene is limited to the toes in old and feeble patients,
some surgeons advocate the expectant method of treatment, waiting for a
line of demarcation to form and allowing the dead part to be separated.
This takes place so slowly, however, that it necessitates the patient
being laid up for many weeks, or even months; and we agree with the
majority in advising early amputation.

In this connection it is worthy of note that there are certain points at
which gangrene naturally tends to become arrested--namely, at the highly
vascular areas in the neighbourhood of joints. Thus gangrene of the
great toe often stops when it reaches the metatarso-phalangeal joint; or
if it trespasses this limit it may be arrested either at the
tarso-metatarsal or at the ankle joint. If these be passed, it usually
spreads up the leg to just below the knee before signs of arrestment
appear. Further, it is seen from pathological specimens that the spread
is greater on the dorsal than on the plantar aspect, and that the death
of skin and subcutaneous tissues