180 Report on the Pathological Anatomy of Fleuro-pneumonia. 
2. It always varies in degree of severity in different parts of 
the same pleura. 
3. Its point of greatest intensity corresponds to the apparent 
starting-point of the lung lesion. 
4. It is not an invariable or essential part of the disease. 
5. It usually appears to be of more acute type and more 
recent development than the lung lesion. 
6. Its occurrence often gives the first indication of the exist- 
ence of disease. 
Lung Lesion. — The situation of the disease in the lung is 
generally obvious, on account of the pleural inflammation being 
more intense over that point. When the pleurisy is absent, or 
is too diffused to indicate the exact position of the affected part, 
it can still be easily recognised as a hard, heavy, airless, and 
discoloured mass, standing out boldly from the neighbouring 
normally collapsed lung tissue, which is soft, light, and elastic. 
The extent to which the organs may be affected varies greatly, 
the size of the diseased area being, as a general rule, in direct 
proportion to the length of time the disease has lasted. Some- 
times the greater part of both lungs appears to be implicated, 
while in others there may only be a nodule the size of a man's 
fist. When looking at the lungs after removal, one is apt to 
think that a greater proportion of them is affected than is really 
the case ; because the diseased part seems to have greater rela- 
tive bulk, when compared with the healthy structure, than it 
has in reality ; for this latter collapses into very insignificant 
dimensions when the thorax is opened, while the size of the 
diseased portion remains unaltered. The correct proportion of 
healthy and morbid parts can only be seen when the organs 
are inflated, by which means the healthy parts are distended to 
their normal size. At first sight I have often felt inclined to 
say that the whole of one lung was engaged, so enormous 
was the hard mass and so general the pleurisy ; but inflation 
brought out many considerable tracts of healthy lung tissue, 
which would have escaped notice had they not been thus dis- 
tended with air. In these cases, where the whole of a lung 
seems diseased, much of the airless part presents on section none 
of the distinctive characters of pleuro-pneumonia, but merely 
those which are due to pressure, or such-like secondary changes. 
Under the present system of slaughter the disease never seems 
to reach the extreme stages which have been described by some 
authors, where the lungs weigh over 100 lbs. As a general rule, 
the morbid processes, which are characteristic of the disease, 
are limited to a comparatively small area, seldom engaging 
more than half the lung, and most commonly only one lobe. 
Where many lobes are diseased, they are found to be affected in 
