ON APHTHOUS DISEASE AMONG CATTLE. 637 
brane of the mouth, the muzzle, round the wings of the nose, and 
in the interdigital space. 
Examined separately, these vesicles are very irregular in form, 
size, and extent. Some are small and resemble grains of millet ; 
others are larger, round, and similar to lentils, slightly prominent 
in the centre. The pellicle which covers them is at first grey, but 
it subsequently becomes white. Others are oblong, undulated at 
the edge, and more or less irregular in form. In most of them the 
fluid they contain is limpid and serous, but it afterwards acquires 
a degree of opacity, that appears to us to arise from numerous 
minute specks that are held in suspension in it. All these cha- 
racters have been observed in the ampullce which exist on the muz- 
zle and snout of pigs. Those which are found in the interior of 
the mouth, on the tongue, and on the circumference of the wings 
of the nose, form blotches of greater or less extent ; resulting, 
doubtless, from the agglomeration of several vesicles. 
The irruption of aphthse localized in the mouth produces a slight 
improvement in the general state of the individual ; but this is not 
the case when they exist in the interdigital space, or on the teats ; 
then the inflammatory symptoms become obstinate, and the limbs 
begin to swell. The patients remain almost constantly recumbent. 
The phlyctsense which in some cases we have observed on the teats 
have not presented any particular characteristic : they were in 
every respect identical with those which existed on the muzzle, the 
lips, and the tongue. 
In the epizootic which we observed, it was impossible to con- 
found the aphthous vesicles with the pustules of scab, or with 
the cow-pox described by Jenner. Nevertheless, as some authors 
have observed certain analogies between them, we shall endeavour 
to define the different characteristics of these three affections. 
SYNOPTIC AND COMPARATIVE TABLE. 
Aphtha. 
They appear under the form 
of epidermic ampullse, without 
any tumefaction or inflammation 
of the skin. The pellicle which 
covers them is grey or white; 
they are not surrounded by an 
areola: there is merely a pale 
red circle, and even this is not 
always found. 
Scab Pustules. 
Patches of red at first on the 
skin ; and nodosity is felt in the 
substance of the skin, which be- 
comes perceptible when the part 
is pinched or folded : to this 
succeeds a white pustule, slight- 
ly depressed in the centre. The 
surrounding parts are hard, in- 
flamed, and painful. 
