168 DISEASES OF THE LUNGS. 



that was_, tliat, by pression, the vesicles could be rendered 

 lax, although no air escaped externally. 



Now, although these might have been cases of em- 

 physema, certainly the interlobular extravasation was not 

 present, neither were the subjects themselves broken- 

 winded. 



The interlobular or true emphysema, Dr. Townsend 

 informs us, "may be easily recognized in the dead body, 

 by the transparency of the interlobular partitions, which 

 contrast strongly Avith the dense structure of the intervening 

 portions of parenchyma. Instead of the scarcely perceptible 

 thinness which they exhibit in the normal state, these parti- 

 tions, in a state of emphysema, are distended to the breadth 

 of two or three lines, or even in some cases of an inch. 

 They are generally widest at the surface of the lung, where 

 the distension of their delicate cells bears an apt re- 

 sem])lance to a string of glass beads.^'' — " 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 trunk.^^ — " Sometimes the air 

 escapes into the cellular tissue which connects the pleura to 

 the lung; forming bubbles of air, which may be pushed 

 along the surface by the finger; by which circumstance they 

 may be distinguished from the vesicles that are formed in 

 true (?) pulmonary emphysema, as the latter are prevented 

 from being displaced in this way by their interlobular parti- 

 tions. Laennec explains this extravasation of air as de- 

 pendent on rupture of air-cells : in most extensive cases of 

 this disease, however, no such rupture has been detected; 

 and rupture of cells constantly takes place without a par- 

 ticle of air getting into these partitions.^^ This is the form 

 of emphysema which we must continue to regard as in- 

 separably connected w ith broken-wind : we have no fact 

 before us to show that this has ever been observed in any 

 but a broken-winded liorse ; although we appear to have 

 evidence to prove that symptoms of broken-wind may exist, 

 and yet the lungs be sound and free from emphysema. 



