158 ON THE NAVICULAR DISEASE AND SPAVIN. 
fection both in shape and action, and was a great favourite of an 
illustrious personage. He suddenly became lame behind, on 
the off-leg, and without the least visible alteration of structure to 
account for it. Circumstances, unfortunately for the poor beast, 
were such, the lameness disappearing after his being turned 
out for a short time, that, instead of being given up immediately 
for treatment, he was made to perform his usual work until per¬ 
fectly incapacitated from it by returning and aggravated lame¬ 
ness. Suspecting the seat of the mischief to be in the hock, al¬ 
though at the time the joint was unaltered in form, he was, three 
months after the commencement of the lameness, blistered and 
fired; after which operations he was either in a loose place or 
paddock, as circumstances required. Not the least amendment 
took place at the end of six months, even in his quiescent state; 
and, after twelve months’ trial from the time of his being given 
up for treatment, he was destroyed, his case being naturally con¬ 
sidered a hopeless one. 
You will perceive, that ulceration of the synovial membrane 
taking its origin between the two cuneiform bones, has ex¬ 
tended to the bones; that they have become carious; and the 
disease has been gradually extending itself to other parts of the 
joint; and I have no doubt that, had the animal been suffered to 
work on for any length of time, necrosis or anchylosis of every 
bone concerned in the hock would have been the result, as 
you may observe has been the case of the hock I now show 
you. 
I know not of any diagnostic marks that would lead us to dis¬ 
criminate the kind of conformation most susceptible to be attacked 
by this disease ; but by drawing your attention to these cases, I 
trust, if your experience confirms that which I have stated to be 
the usual cause of these lamenesses, some more light may be 
thrown on a most important part of veterinary practice. 
It is necessary to have a true notion of causes before we com¬ 
mence treatment for effects. And I shall now pause until I hear 
how far the opinion of others corresponds with my own on this 
