ON EMPHYSEMA OF THE LUNGS. 
635 
is, perhaps, no class of complaints in which the beneficial effects 
of change of air and climate are more decidedly manifested than 
in those chronic cases of pulmonary emphysema complicated 
with great susceptibility of irritation in the mucous membranes 
of the air-passages.—(See Climate.) 
II. Interlobular Emphysema. —This, as its name implies, con¬ 
sists in an effusion of air into the cellular tissue, which intersects 
the pulmonary parenchyma, and divides each lobe into a number 
of distinct lobules. This form of pulmonary emphysema may 
be easily recognized in the dead body, by the transparency of the 
interlobular partitions, which contrast strongly with the denser 
structure of the intervening portions of parenchyma. Instead of 
the scarcely perceptible thinness which they exhibit in the na¬ 
tural state, these partitions, in a state of emphysema, are dis¬ 
tended to the breadth of two or three lines, or even of an inch in 
some cases. They are generally widest at the surface of the 
lung, where the distention of their delicate cells bears an apt re¬ 
semblance to a stringof glass beads. Sometimes the emphysema 
is confined to two or three interlobular partitions, which run pa¬ 
rallel to each other from the margin of the lung; in some cases 
these parallel bands are intersected by transverse partitions like¬ 
wise in a state of emphysema, and the lobules intercepted between 
these intersecting partitions are thus completely insulated, being 
surrounded on all sides by transparent cellular tissue in a state 
of emphysema. 
When the disease continues to extend, the air passes from one 
interlobular partition to another until it reaches the root of the 
lung, from whence it soon extends to the mediastinum, and 
thence spreads all over the cellular tissue of the trunk.—(See 
Emphysema.) 
It sometimes happens in this form of the disease that the air 
escapes into the cellular tissue which connects the pleura to the 
lung; in this way one or more bubbles of air are formed im¬ 
mediately under the pleura, and may be pushed along the surface 
of the lung by the finger,—by which circumstance they may be 
distinguished from the vesicles that are formed in the true pul¬ 
monary emphysema, as the latter are prevented from being dis¬ 
placed in this way by their interlobular partitions. 
The formation of interlobular emphysema is explained by 
M. Laennec as necessarily depending on a rupture of some of the 
air-cells, and the consequent extravasation of the air contained in 
them into the cellular substance surrounding the lobules. It 
must, however, be admitted that, even in the most extensive 
cases of this disease, no such rupture has ever been detected, and 
that the rupture of several cells constantly takes place, and yet 
