544 
N A VICUL ARTHRITIS. 
Temedies which had before proved successful, failed ; and Mr. H. 
had come to the conclusion that his case was navicular , and that, 
therefore, his condition was hopeless; on hearing which opinion the 
owner took him and drove him seventeen miles in a carriage, the 
consequence of which was an attack of acute founder ( laminitis ) 
of which, on the sixth day, he died. Upon the inferior surface 
of the navicular bone, in its centre, was discovered “ a dark red 
spot,” and “ very small spiculse of bone were beginning to shoot 
through the articulating cartilage.”. This shews the cartilage was 
in the preparatory condition for ulceration. 
When, on the other hand, navicularthritis steals on by degrees — 
as is the usual mode of its attack — we have evidence sufficient 
that inflammatory action has set in, and to this we are bound to 
ascribe most, if not all, of the anormal phenomena which follows 
In this case, the probability is, that the injury giving rise to the 
inanimation amounts to no more than a contusion or bruise of the 
synovial membrane; and this is Mr. Turner’s opinion: — “lam 
thoroughly convinced,” says he, “that this complaint (navicular- 
thritis) at its commencement, is neither more nor less than a bruise 
of the synovial membrane lining the joint.” 
Brauell tells us that the commencement of the disease is usually 
marked by “ either inflammation of the bursal membrane only, or 
of that and the navicular. The superior portion of the bursa which 
unites with the superior border of the navicular bone, and is con- 
tiguous to the tendon, presents upon its internal surface a blush of 
redness, accompanied at times with slight tumefaction. The por- 
tion which covers the trochlear cartilage, as well as the anterior 
surface of the tendon, has lost its pearly whiteness, and taken on 
a saffron hue. And the bursa itself is frequently thickened. The 
fluid contained within the bursa is of a reddish hue. The vessels 
passing underneath the navicular are often found injected ; and 
the flexor tendon at its insertion often has the appearance of 
having been compressed at its sides : its anterior surface looking 
wrinkled.” — “ When the navicular bone is inflamed it is red and 
strongly injected. The vessels traversing it are dilated. But when 
macerated, it is found to have decreased in weight — its texture to 
have become more porous ; occasionally the bone having a puffy 
appearance.” 
Inflammation having set in, what follows? — Remem- 
bering that the inflamed tissue is a secreting structure, and being 
acquainted by observation with what happens in like circum- 
stances in other joints, we are prepared to meet with 
Defective secretion of synovia. The late Professor Cole- 
man had observed this change ; and the fact has since received 
ample confirmation at the hands of Mr. Turner, whose words are—’ 
