CHANGES THE LUNGS UNDERGO IN PNEUMONIA. 369 
The foregoing abstracts of cases constitute, as far as they go, 
a body of facts from which we may hazard to make deductions of 
sufficient accuracy to meet all but extraordinary or incidental 
occurrences. The ordinary subject of pneumonia or pleuro¬ 
pneumonia is the horse at a period of life when his vascular 
system is in its fullest force of activity, which, in most instances, 
is increased by stimulating diet, stimulating stable atmosphere, 
and perhaps exertion of body as well. Seeing, then, the fire 
of inflammation lighted up in a constitution so favourable to 
its progress, and seeing the flame thus fanned within it by 
various agents from without, need we feel any surprise at the 
rapidity with which it hastens through its various stages, to the 
production of the most disastrous consequences. Should the 
violence and intensity of pleuritic or pleuro-pulmonic inflam¬ 
mation not carry the animal off in the first week of his illness, 
the obliteration, through hepatization, of the air-cells and ex¬ 
treme ramifications of the bronchi, is likely to do so, if extensive, 
in the course of the second week; and should the case run into 
the third, or be protracted to the fourth week, we may expect 
to find, at our autopsial examination, tubercles of the granular 
class, with abscesses of the cells, as well as the white cheesy 
conversion of such tubercles which may be regarded as suppu¬ 
ration of them. 
General as these observations are intended to be, and exclu¬ 
sively applicable as they manifestly are to acute disease in 
young and vigorous subjects, without the pale of this range 
they have, of course, no reference. Very many exceptions are 
to be met with in practice, owing to modification of disease, 
difference of subject, of circumstances, &c.; but these nowise 
invalidate the general facts : facts, as it has been seen, deduced 
from results in practice which do not admit of being gainsaid. 
The subjects being horses under the immediate cognizance, as 
well in health as in disease, of myself, and being so situated that 
the first signs or indications of ill health could not but at once 
reach my ears, there is no room for doubt or suspicion as to the 
date of commencement of the disease being ail but synchronous 
with that of being taken “ under treatment/’ no more than that 
the disease constituted a primary attack. 
