ON APHTHOUS DISEASE AMONG CATTLE. 
668 
Cow-Pox. 
The pustules of cow-pox are flat, circular, indented in the centre, 
with a prominent base, and surrounded by a reddish halo, which 
insensibly becomes livid. They soon become diaphanous, and 
assume a silvery reddish hue*. 
Third Stage. 
The period at which the ampullae ulcerate is variable, those in 
the mouth reaching this point sooner than those in the interdigital 
space. 
The ulceration of the former follows closely upon their appear- 
ance. It is outwardly manifested by an abundant salivation, which 
is ropy, and sometimes streaked with blood, and by the great 
quantity of slaver which is found in the manger, and at the commis- 
sures and borders of the lips. 
Independently of these symptoms, which are always present, the 
tongue is frequently in motion, shews itself outside, passes over 
the muzzle, and is then withdrawn into its cavity again. Its 
epidermis can be raised with the greatest facility, just as if it had 
been steeped in boiling water. Frequently has it happened that, 
when we have taken hold of it, patches as large as a crown 
piece have come off in our hands, covered with superficial ulcera- 
tions, bloody, and of a vivid red colour. Those of the internal 
surface of the cheeks, lips, and gums, appeared as if they had been 
made with a nipping-tool. The mouth is hot and painful, and the 
animal struggles when any one attempts to examine it. 
Where there is no complication, this state of things will last 
three, four, five, six days, but never more than six days ; after this, 
all the symptoms begin to diminish. The progress of the exterior 
vesicles is not so rapid ; it is seldom affected within six-and-thirty 
or forty-eight hours. The aspect of these ulcers is not so repulsive 
as those of a chancrous description. They are superficial, smooth, 
shining, and covered by a purulo-sanguinolent and viscous mat- 
ter, which is soon formed into a thin reddish crust by contact with 
the air. 
Some ulcers become serious from their position ; for example, 
those which are situated in the fatty part of the foot cause a dis- 
union between it and the crust at the heel, and in the direction of 
the commissures; and the inflammation, local in the first in- 
stance, spreads to the vascular tissue of the foot and occasions even 
* Note. We have never seen the cow-pox. These characteristics are ex- 
tracted from Hurtrel d’Arboval’s “ Dictionnairc.” 
