DISEASES OF THE SKIN AND SLé TISSUES 233 
Purpura Hemorruaaica (“Scurvy ”. 
A disease not unfrequently makes its appearance among horses 
wwrmed purpura hemorrhagica, known in human practice as the 
“purples.” It consists of congestion (extravasation) blood of and 
effusicn of serum (water) into the cellular tissue. The disease 
probably owes its origin to a depraved condition of the blood. 
Symptoms.—On making an examination of the affected animal, 
we find that the cellular tissue, in various parts of the body, is 
distended with serum and blood. Local swelling will appear in 
various parts of the body, more particularly about the face, lips, 
and limbs. ‘The disease also affects internal parts. Blood is 
sometimes passed with the urine and feces; respiration is embar- 
rassed ; the heart palpitates, and abnormal cerebral symptoms set 
in. In the human subject the disease is considered strictly as a 
hemorrhage. Small round spots appear on various parts of the 
body and legs, of a dull crimson or purple color. Pressure upon 
them does not efface the color, nor render it fainter, as it does that 
of common inflammatory spots of the skin. There is scarcely any 
prominence of the purple stigmata; but they are sometimes inter- 
mixed with livid blotches, with appearances exactly resembling 
bruises, and they undergo, before they disappear, the same changes 
in color which attends the disappearance of a bruise. In fact, the 
anatomical condition of a bruise is exactly the same, with the dif- 
fused condition as in purpura. In each case the color is the result 
of echymosis (effusion of blood beneath the skin). 
In the human subject, also, the disease is not confined to the 
skin. WATSON informs us that “ the spots are not confined to the 
skin, nor to the subcutaneous tissues, but are found, occasionally, 
upon all the internal surfaces also, and within the substance of 
the several viscera (internal organs of the body). I have seen 
these purple spots in the mucous surface of the mouth, throat, 
stomach, and intestines; in the pleura and pericardium; in the 
chest; in the peritoneal investment of the abdominal organs; in 
the substance of the muscles, and even upon the membranes of 
the brain and in the sheaths of the large nerves, and I have known 
them to be accompanied with large extravasations of blood in most 
of the vital organs of the body.” 
The same appearances have been observed in equine autopsies, 
which accounts for the immehility and deranged condition of all 
