PRACTICE OF VETERINARY MEDICINE. 
565 
before. From this period it is seldom that the patient really im- 
proves, although symptoms seemingly to that effect occasionally 
appear, but only, as it were, to deceive the perhaps anxious prac- 
titioner. The animal gradually passes from a bad to a worse state, 
until, at last, it dies an exhausted, emaciated, and sometimes loath- 
some, object. 
Prognosis of Purpura. — In the very scanty, but very excellent, 
observations* written by John Field upon this disease, in speaking 
of its prognosis he says, it “ must be guarded, and can only be 
favourable when the fever has abated; when the swellings are 
confined to the limbs, not attended with difficulty in motion ; when 
symptoms of internal mischief are absent ; when there is plentiful 
diuresis : but if the urine be scanty, ropy, voided in small quan- 
tities ; if there be much painful distention of the thighs from effu- 
sion beneath the faschia ; if there be much extravasation about 
the nose and head, and effusion beneath Schneider’s membrane, 
&c., the prognosis is unfavourable, and, moreover, if symptoms of 
internal disease exist.” 
Having thus briefly considered purpura with respect to its na- 
ture, its predisposing and exciting causes, its varieties, complica- 
tions, diagnosis, duration and prognosis of the disease, we may 
now, as briefly, enter upon the consideration of scarlet fever. 
Scarlet fever is another disease which is without place, and almost 
without mention, in our systematic treatises on veterinary medi- 
cine : the only writer who alludes to it is Mr. Percivall, in whose 
work, vol. ii, page 27, the reader will find some observations 
respecting it. From what Mr. Percivall states, it appears that its 
nature was first recognised by himself; and that he called the at- 
tention of the profession to it in a paper which he wrote and pub- 
lished in The Veterinarian so early as the year 1834. From 
that time to the present, a period of sixteen years, one would 
naturally expect that our knowledge of this disease would be of a 
very complete character; but I should greatly question whether, 
upon the whole, it is much better understood now than what it was 
then ; at any rate, our knowledge of it is very far from what it 
ought to be, considering the opportunities which the members of 
the profession at large must have had for investigating it. 
Scarlet fever, with reference to the human being, “ is, for the 
convenience of description,” says Watsont, “and for the better di- 
rection of the treatment,” generally by authors considered under 
three varieties, viz., scarlatina simplex , in which there is a florid 
rash, and little or no affection of the throat ; scarlatina anginosa , 
in which both the skin and the throat are decidedly implicated ; 
* See his “ Posthumous Extracts,” page 18. 
f See Watson’s “ Lectures on the Principles and Practice of Physic,” 
VOL. XXI11. 4g 
