syphilis, from an innocent tumour, and from a cancer. The points on
which the diagnosis is founded are discussed with the different tissues
and organs.

_Treatment._--The removal of the tumour by operation is the most
reliable method of treatment; in order to be successful it must be
undertaken before dissemination has taken place, and a considerable area
of healthy tissue beyond the apparent margin of the growth must be
removed, and in tumours near the surface of the body, the overlying skin
also.

In order to prevent recurrence, a tube of _radium_, to which a silk
thread is attached, is inserted into the space from which the tumour was
removed; the thread is brought out at the drain-opening, and at the end
of a week or ten days the tube of radium is removed by pulling on the
thread. Radium causes a reaction in the tissues attended with exudation
from the vessels, for the escape of which provision must be made. If
radium is not available, the affected area is repeatedly exposed to the
action of the _X-rays_ as soon as the wound has healed. The employment
of these measures has diminished to a remarkable degree the recurrence
of sarcoma after operation.

It will readily be understood that the less thoroughly or radically the
growth has been removed, the more do we depend upon radium or the X-rays
for bringing about a permanent cure, and that in advanced cases of
sarcoma and in cases in which, on account of their anatomical situation,
removal by operation is necessarily incomplete, the prospect of cure is
still more dependent on the use of radium or of the X-rays. Finally,
there are cases in which removal by operation is impossible, the
so-called _inoperable sarcoma_; a tube of radium, to which a silk thread
is attached, is inserted into the substance of the tumour, either
through an opening made by a large trocar, or, when necessary, by open
dissection. A second tube of radium is placed upon the skin over the
tumour and is secured there by a stitch or by a strip of plaster, thus
securing a cross-fire action of the radium rays, both from within and
without, as this is found to be much more efficacious in destroying or
inhibiting the cellular elements of the growth. The tubes of radium are
left _in situ_ for from eight to fourteen days, according to the power
of the radium employed, but are moved about every second day or so in
order that every part of the tumour may be efficiently radiated. If the
tumour shrinks in siz