CONSUMPTION OF THE LUNGS. 



215 



this result is rare, and only occurs when a pathological cavity has 

 formed, enclosing the inflammatory products. The explanation is, that, 

 in the lungs, natural cavilies already exist, and it is in these that in- 

 flammatory products are usually deposited. 



We must emphatically express our dissent from the theory that 

 caseous infiltration of the lung, with its concomitant formation of 

 vomicse, has its source in a form of primary inflammation of peculiar 

 nature, which is distinguishable from other varieties of pneumonia. 

 The hypothesis of a "tuberculous or caseous inflammation of the 

 lung " is entirely untenable, and only tends to cause fresh confusion. 

 On the contrary, it may be said, with perfect truth, that all forms of 

 pneumonia may end in caseous infiltration under certain conditions, 

 and that there is no form of pneumonia of which caseous infiltration 

 is a sole and constant termination. It is true that the difference is 

 very great in the frequence with which the inflammatory products of 

 the various forms of pneumonia undergo cheesy transformation instead 

 of liquefaction and absorption. In croupous pneumonia such a result 

 is rare ; in acute catarrhal pneumonia it is somewhat more frequent, 

 while in the chronic catarrhal form it is almost the rule. 



I regard the name chronic catarrhal pneumonia as the only title 

 appropriate to the form of disease usually called infiltrated tubercu- 

 losis, and gelatinous or tuberculous infiltration, and which latterly and 

 with equal impropriety has sometimes received the name of tubercu- 

 lous or of cheesy pneumonia. This lobular infiltration, or (when the 

 disease is extensive, as it often is) this lobar infiltration of the lungs, 

 with its homogeneous section and its color and glitter of frog-spawn, is 

 not dependent simply upon a filling of the air-vesicles with young 

 spherical cells of indeterminate nature, that is to say, with the ana- 

 tomical products of catarrhal pneumonia, but arises, with rare excep- 

 tions, through extension of a chronic catarrh, with a copious secretion 

 of young cells, into the finer terminal bronchioles, and thence into the 

 pulmonary vesicles. I certainly should attach little weight to the 

 application of the name chronic catarrhal pneumonia to the so-called 

 gelatinous pneumonia, did I not believe that, by calling the disease by 

 its proper name, not only is our comprehension of the etiology and 

 pathology of the malady facilitated, but its prophylaxis and thera- 

 peusis are promoted. It is not difficult to understand why chronic 

 catarrhal pneumonia should generally give rise to caseous infiltration, 

 far more frequently, indeed, than the acute form of the disease, or than 

 croupous pneumonia. Owing to the slowness and tedious nature of its 

 progress, the tendency of which is to a perpetual accumulation of 

 young cells in the air-vesicles, perhaps also by an inhalation of cells 

 from the smaller bronchi, thus adding still more to those already 



