ON EMPHYSEMA OF THE LUNGS. 
627 
of a garden-pea. In the great majority of cases the cavities of 
this size, or even of a less diameter, are formed by several cells 
being thrown into one, in consequence of their delicate partitions 
being overstrained and ruptured. In some cases, the walls of 
the cells disappear from one entire lobule, leaving only some 
lacerated filaments traversing its cavity from one interlobular 
partition to another ; and in some instances these partitions are 
also lacerated, and their respective lobules are thus thrown into 
one large cavity, which usually reaches the surface of the lung, 
and forms a projection under the pleura. In order to see these 
alterations of structure, it is necessary to inflate the lung and 
, m 7 *' # o * 
dry it previous to examination, as without this precaution the 
cells collapse immediately when cut into, and all appearance of 
emphysema is consequently lost. 
“ Emphysema may affect both lungs at the same time, one 
only, or a part of one, cr both : in the latter case, and, indeed, 
in any case, as long as the disease is confined to a simple dila¬ 
tation of the cells, or to the rupture of a few of their partitions, 
and does not form vesicles of any considerable size on the sur¬ 
face of the lung, it may be easily overlooked in the dead body : 
for this reason, the disease, which is really one of the most 
constant morbid appearances in all cases of protracted dyspnoea, 
has been as constantly overlooked ; and in this way the lungs of 
asthmatic patients have been regarded as healthy when they are 
in reality emphysematous, and cases of dyspnoea set down as 
nervous or idiopathic, for which anatomy has now discovered an 
organic cause. 
“ When the disease exists in a very high degree, we cannot 
help being struck with the appearance of the parts. The lungs 
seem as if confined within their natural cavity, and when ex¬ 
posed, instead of collapsing as usual, they rise in some degree, 
and project beyond the borders of the thorax. If we examine 
them in this state, they feel firmer than natural, and it is more 
than usually difficult to flatten them. The crepitation they yield 
on pressure, or being cut into, is less, and of a kind somewhat 
different; it is more like the sound produced by the slow escape 
of air from a pair of bellows, and the air makes its escape from 
the cells much slower than in a healthy state of the organ. 
When we detach the lung, the crepitation is found to be still 
less perceptible, and the sensation conveyed by pressing the 
parts is very like that produced by handling a pillow of down. 
On placing an emphysematous lung in a vessel of water, it 
sinks much less than a healthy lung, and sometimes it floats on 
the surface with scarcely any obvious immersion. The pulmo¬ 
nary tissue is drier in a lung affected with pmphysema than in 
