osit of blood
pigment; on its surface, and in parts of the articular cartilage, there
is a deposit of rust-coloured fibrin; there may be extensive adhesions,
and in some cases changes occur like those observed in arthritis
deformans with erosion and ulceration of the cartilage and a form of dry
caries of the articular surfaces, which may terminate in ankylosis.

As the swelling of the joint is associated with wasting of the muscles,
with stiffness, and with flexion, the condition closely resembles
tuberculous disease of the synovial membrane. From errors in diagnosis
such joints have been operated upon, with disastrous results due to
haemorrhage.

The treatment of a recent haemorrhage consists in securing absolute rest
and applying elastic compression. The introduction of blood-serum (10-15
c.c.) into a vein may assist in arresting the haemorrhage;
anti-diphtheritic serum is that most readily obtainable.

After an interval, measures should be adopted to promote the absorption
of blood and to prevent stiffness and flexion; these include massage,
movements, and extension with weight and pulley.

JOINT DISEASES ASSOCIATED WITH LESIONS OF THE NERVOUS SYSTEM:
NEURO-ARTHROPATHIES

_In Lesions of Peripheral Nerves._--In the hand, and more rarely in the
foot, when one or other of the main nerve-trunks has been divided or
compressed, the joints may become swollen and painful and afterwards
become stiff and deformed. Bony ankylosis has been observed.

_In Affections of the Spinal Medulla._--In myelitis, progressive
muscular atrophy, poliomyelitis, insular sclerosis, and in traumatic
lesions, joint affections are occasionally met with.

The occurrence of joint lesions in _locomotor ataxia_ (tabes dorsalis)
was first described by Charcot in 1868--hence the term "Charcot's
disease" applied to them. Although they usually develop in the ataxic
stage, one or more years after the initial spinal symptoms, they may
appear before there is any evidence of tabes. The onset is frequently
determined by some injury. The joints of the lower extremity are most
commonly affected, and the disease is bilateral in a considerable
proportion of cases--both knees or both hips, for instance, being
implicated.

Among the theories suggested in explanation of these arthropathies the
most recent is that by Babinski and Barre, which traces the condition to
vascular lesions of a syphilitic type in the articular arteries.

The first symptom is usua