42 
THE EDINBURGH VETERINARY COLLEGE. 
the perverted direction of the motion of the bones on each other : 
but, notwithstanding this, and although, for a considerable time, 
little apparent inconvenience is produced, it ultimately happens, if 
the animal is continued at work, that the enlargements about the 
hock become encrusted by osseous deposits, which interfere with 
the action of the joint, while the interior of the articulation is 
abraded, so that, although in the milder cases the articular cartilage 
is simply marked by slight ridges, yet in the older and more 
severe ones the articular surfaces of the astragalus and inferior 
end of the tibia become so worn that they exhibit an appearance 
like polished ivory, giving rise to what has been by some patho- 
logists termed “ porcelainous deposit,” and in more severe and 
advanced cases still, this appearance has been worn off, and the 
cancellated structure of the bones is exposed. The “ porcelainous 
deposit” as it has been called, is, however, nothing more than the 
hard shells of the bones simply polished by their friction against 
each other. This kind of friction takes place in all cases where the 
capsular ligament is distended with synovia, and will be easily 
traced in every case of tbe kind. The sulci which are found in 
all large and well-formed joints, and which are natural to them, 
must not, however, be mistaken for what is here referred to; for 
although the sulci are, in some respects, like ulcers in their appear- 
ance, they, even in that, are totally different from the effects of 
friction, in which case the articular surfaces of the cartilages and 
bones present appearances as if turned in a lathe. The treatment 
of such cases as these is generally counter-irritant in its nature ; 
but moderate work, until the animal arrives at maturity, will be 
the best means of relieving the disease, and, perhaps, of averting it 
altogether. 
The case of quittor, under the head “ neat cattle,” occurred in a 
valuable half-bred cow, the property of a dairy-keeper, near the 
College. Assistance was applied for on the 10th Nov., and on 
examining the case it was found that in the near hind foot there 
were several deep sinuses, extending from the coronets of both 
digits into the interior of the foot. One large sinus passed from 
the anterior to the posterior part of the foot, between and some- 
what above the digits, and above the interdigital ligament, ex- 
posing the extensor tendon as it passes on each side to its insertion. 
Two other sinuses were situated near and on each side of the 
larger one ; that on the outer side of the limb communicated with 
the cavity of the articulation between the large and small pastern 
bones. The history given of the case by the owner was, that 
about a fortnight previously the cow exhibited slight laun ness on 
the foot affected, which when he examined he found to be hot, 
painful, and swollen. He treated her for some time himself, and 
