116 MR YOUATt’s veterinary LECTURES. 
of the respiratory passages, and, in fatal or aggravated cases, of 
the mucous membranes generally. From the pharynx, to the 
termination of the small intestines, and often including even the 
larger ones, there will not be a part free from inflammation. 
Ulcerations will often be found in the pharynx. The larynx, and 
particularly the rimse glottidis, will be thickened or ulcerated; 
the upper part of the trachea will be filled with adhesive spume, 
and the lining membrane thickened, injected, or ulcerated ;—the 
lining tunic of the bronchi will exhibit unequivocal marks of in¬ 
flammation ; the substance of the lungs will be engorged, and 
often inflamed : the heart will partake in the same affection—its 
external coat will be red, or purple, or black, and its internal one 
will exhibit spots of ecchymosis ; the pericardium wall be thickened, 
and the pericardiac and pleuritic bags will contain an undue 
quantity of serous, or bloody-serous, or purulent ffuid. 
The oesophagus will be inflamed, sometimes ulcerated—the 
stomach always so; the small intestines will uniformly present 
patches of inflammation or ulceration. The liver will be inflamed 
—the spleen enlarged—no part, indeed, will have escaped; and 
if the malady has assumed a typhoid form in its latter stages, the 
universality and malignancy of the ulceration would scarcely be 
credible. 
Epidemic .—This disease is clearly attributable to atmospheric 
influence, but of the precise nature of this influence we are alto¬ 
gether ignorant. It is some foreign injurious principle which 
mingles with and contaminates the air, but whence this poison 
is derived, or how it is diffused, we know not. It is engendered, 
or it is most prevalent, in cold ungenial weather; or this weather 
may dispose the patient for catarrh, or prepare the tissues to be * 
affected by causes which would otherwise be harmless, or which 
may at all times exist. 
It is most frequent in the spring of the year, but it occasionally 
rages in autumn and in winter. It is epidemic; it spreads over 
large districts. It sometimes pervades the whole country. Scarcely 
a stable escapes. Its appearance is sudden, its progress rapid. 
Mr. Wilkinson had 36 new cases in one day. I have been told 
of a celebrated practitioner in London w'ho had nearly double 
that number in less than twenty-four hours. 
Endemic .—-At other times it is endemic. It pervades one town ; 
one little tract of country. It is confined to spots exceedingly 
circumscribed. It is dependent on atmospheric agency, but these 
require some injurious adjuvant; or the principle of contagion 
must be called into play. I have known it rife enough in the 
lower parts of London, while in the upper and north-western 
districts scarcely a case occurred. Not many weeks afterwards 
