166 DISEASES or THE LUNGS. 



Laennec, is, according to the latter, of two kinds — vesicular 

 and interlobular. Vesicular or pulmonary emphysema con- 

 sists either simply in the dilatation of the minute bronchi 

 and air-cells, or in the rupture of the parietes of several 

 contiguous cells, and their consequent dilatation into one; 

 interlobular J in the infiltration of air, in consequence of 

 rupture of the membranous partitions between the lobules 

 of air-cells, into the cellular tissue interposed between the 

 lobules, and connecting them together. Mr. Stokes,^ how- 

 ever, has very properly objected to the simple dilatation 

 of the air-cells being so classed, "inasmuch as emphysema 

 is not the principal characteristic of the disease, and 

 though a frequent yet by no means a constant com- 

 plication.^^ 



Laennec says, the dilated cell, though it commonly does 

 not exceed a millet-seed, may reach the magnitude of a 

 cherry-stone or French bean f Dr. Townsend, however, in 

 more than one hundred dissections which he made of 

 emphysema, "never, except in one instance, saw the air-cell 

 dilated to the size of a garden-pea.^^ In the majority of 

 cases, such cavities are formed by several cells being thrown 

 into one, in consequence of their delicate partitions being 

 overstrained or ruptured. In this manner, one entire 

 lobule may become one (single) cell; or the interlobular 

 partitions may themselves be lacerated, "and their respective 

 lobules thrown into one large cavity, which usually reaches 

 the surface of the lung and forms a projection under the 

 pleura/^'^ 



I have myself on several occasions met with vesicles on 

 the surface of the lungs — owing to the presence of air 

 underneath the pleura, and the consequent elevation of the 

 membrane — which were not influenced by inflation nor 

 removable by pression ; nor would the air they contained 

 support combustion. These were, none of them, cases of 



1 In his ' Treatise on the Diseases of the (Human) Chest.' 

 ^ In an excellent article on ' Emphysema,' in the ' Cyclop, of Pract. Medicine.' 

 3 The best method of demonstration in these cases is to dry the lung; 

 previous to which, if requisite, it may be inflated. 



