178 VETERINARY MEDICAL SOCIETY. 
Preparatory to the production of some morbid specimens illus¬ 
trative of the occult contraction, I beg to read to the Society a 
few remarks thereon. 
At our last meeting Mr. Goodwin expressed a doubt as to the 
existence of the disease which I have attempted to describe as 
antecedent to navicular lameness; and retorts upon me, that he 
has exercised all his “ tact , talent , and discrimination” in vain 
to find it; but this gentleman, with his usual candour, has ac¬ 
knowledged, that, on being called to the commencement of navi¬ 
cular lameness, confined to one foot, he has not been in the 
habit of removing the shoe, at the same time, from the sound foot, 
for the express purpose of accurately comparing them, and con¬ 
trasting the hollow base or ground surface of the lame with that 
of the sound foot, on the removal of an equal quantity of horny 
sole from each; and therefore I mean to say, that Mr. Goodwin 
has not availed himself of a very important criterion in his inves¬ 
tigation, viz. the comparative difference between the two feet, as 
it regards the elevation of the coffin bone from the ground or 
within the hoof. 
We are not, however, to expect navicular lameness to accom¬ 
pany every case of the occult contraction, as its presence depends 
more on the suddenness with which the horny cavity is lessened 
than on the actual loss of space sustained ; for instance, both fore 
feet may become affected at the same time with this species of 
contraction from below' upwards by very slow degrees, originating 
merely in an inordinate strength of hoof, depriving the sole of its 
natural flexibility, and causing an undue ascent of the bars and 
frog, or a morbid protrusion of these parts. But the animal not 
being further exposed by long confinement in his stall, and 
having his daily exercise or moderate work, Nature sometimes 
effects a corresponding alteration in the shape of the coffin bone, 
by absorption, which renders its inferior surface preternaturally 
hollow, more particularly at the heels, and thus it is enabled to 
descend under the impression of weight, although imperfectly, 
yet enough to avert that contusion or bruise of the synovial mem¬ 
brane of the navicular joint to which this delicate tissue is sub¬ 
ject when opposed in its descent. 
With reference to the treatment I have recommended, Mr. 
Goodwin cannot see in what way the excision of the incurvated 
quarter of the crust at the inside heel can facilitate the return or 
depression of the outside heel of the coffin bone. If Mr. Good¬ 
win had a solid body embraced by a vice, and he wished to loosen 
its hold, it certainly would be necessary to move only one cheek 
or gripe of the vice for that purpose : in like manner the inside 
heel or wing of the coffin bone is frequently hampered by the 
