constitutional disturbance. Several bones may be
affected at the same time, and large pieces of them may be killed
outright (_multiple necrosis_) by inflammatory engorgement and
devastating abscess.

Septic ostitis may be confounded with erysipelas and rheumatism, but
the central thickening and tenderness should suffice to distinguish it.

_Chronic ostitis_ and _periostitis_ denote long-continued and increased
vascular supply. This may be due to injury, syphilis or rheumatism. The
disease is found chiefly in the shafts of the bones. There is a dull
pain in the bone, which is worse at night, and the inflamed piece of
bone is thickened and tender. The lump thus formed is called a _hard
node_, and its outline shows clearly by X-rays. The affected limb should
be rested and kept elevated. Leeches and fomentations may ease the pain,
and iodide of potassium is the most useful medicine.

_Chronic inflammation of tuberculous origin_ affects the soft,
cancellated tissue of such bones as the vertebrae, and the bones of the
hands and feet, as well as the spongy ends of the long bones. In
tuberculous ostitis the presence of the bacilli in the spongy tissue
causes an escape of colourless corpuscles from the blood, which,
collecting around the bacilli, form a small greyish white heap, a
_tubercle_. These tubercles may be present in large numbers at the
expense of the living tissue, and a _rarefying ostitis_ is thus
produced. Later the tubercles break down and form tuberculous abscesses,
which slowly, and almost painlessly, find escape upon the surface. They
should not be allowed to open spontaneously, however, as the wounds are
then likely to become infected with pus-producing germs, and fuel being
added to the fire, as it were, destruction advances with increased
rapidity. The treatment for these tuberculous foci is to place the limb
or the part at absolute rest upon a splint, to give plenty of fresh air
to the patient, and to prescribe cod-liver oil and iron. And when it is
seen that in spite of the adoption of these measures the tuberculous
abscess is advancing towards the surface, the surgeon should cut down
upon the part, scrape out the foci, and disinfect with some strong
antiseptic lotion. Consideration should also be given to the treatment
by injection of tuberculin.

_Caries_ (rottenness, decay) is the name given to tuberculous disease of
bone when the tubercles are running together and are breaking down the
cancellous ti