PRACTICE OF VETERINARY MEDICINE. 
67 
attacks “all four legs;” that its terminations are “ very apt to be 
true farcyand that “ now and then it will run into a virulent 
attack of grease*.” Now, my experience hitherto does not confirm 
any one of these statements. I have never seen a case where all, 
nor yet two, of the limbs were actually affected at the same time; 
but I have known one hind limb to be so acted upon, and then the 
other immediately upon the recovery of the first; and in one case 
the disease began in the left fore leg, which recovered, and was 
followed by its development in the hind extremity of the same 
side. I scarcely think that a disease so acute in its nature as the 
one in question could be so general, or act over such a large ex¬ 
tent of surface at once; nevertheless, I am not prepared to totally 
deny the possibility of any such thing. Again, with respect to its 
terminating in farcy, I have simply to state, that I never yet knew 
such to be the fact: it is altogether different in its nature from 
true farcy, and different also in its terminations; neither did I 
ever know it to be succeeded by a “ virulent attack of grease;” but 
I have known it produced from suddenly checking the discharge 
from a greasy limb of long standing, and to disappear upon the 
renewal of such discharge. I might enlarge yet further upon this 
matter, and state a variety of results which I have obtained in my 
observations upon this peculiar disease, but for the present I will 
refrain from so doing, as I intend, at some future time, to devote a 
paper entirely to its elucidation. I shall, therefore, proceed to the 
consideration of the last part of our subject, and close this already, 
I fear, too lengthy contribution. 
Megrims is another disease respecting which very little is 
known beyond its mere externalities. The causes which produce 
it do not appear to have been sought into with that care and 
energy necessary to establish its true pathological conditions. 
Mr. Percivall says that “ the pathology” of this disease “ remains 
undeveloped;” any facts, then, which tend to its elucidation in any 
particular, must be regarded as an advance into this intricate 
question. The facts which I have contributed in the present case 
are of that nature. The state of the brain, and more particularly 
of the arteries situated at the base of that organ, prove most 
unquestionably what were, or rather what was, the immediate or 
excitant cause of the vertiginous fit. The canal of the vessels 
being obliterated, prevented a sufficiency of arterial blood from 
going to the brain; and when the animal was over driven, the 
brain not receiving the necessary stimulus to maintain the extra 
call upon its powers, giddiness and coma rapidly supervened, and 
consciousness was only restored after the animal power and 
circulatory organs were allowed to settle to their previous regu- 
* See Mr. Percivall’s admirable work, vol. i, pages 322 and 324. 
