GANGRENE OF THE LUNGS. 207 



eedure actually represses the secretion, and we can easily convince our- 

 selves that, after an inhalation of a quarter of an hour, violent coughing 

 follows, and evacuation of the cavities is effected. The inhalations are 

 repeated three or four times daily, and I have seen patients raised by 

 this means from a condition of extreme misery to one of tolerable 

 comfort, which lasted for some time. 



CHAPTER XII. 



GANGRENE OP THE LUNGS. 



ETIOLOGY. Various forms of mortification have already come under 

 our notice in the foregoing chapters, among others, that of abscess as a 

 sequel of pneumonia, and disintegration of the pulmonary parenchyma 

 as a consequence of haemorrhagic infarction. Mortification proper, 

 gangrene of the lung, differs from these forms of necrosis, inasmuch as 

 the dead part putrefies and undergoes chemical decomposition. Putre- 

 factive decomposition of necrotic parts of the economy occurs most 

 commonly in organs which are exposed to contact with the air, such as 

 the skin and the lungs, while in the brain, the liver, and the spleen, 

 as long as they remain within their normal envelopes, putrefaction of 

 dead tissue is not so apt to occur. The transition of necrosis into 

 ^angrene is materially promoted if a " ferment " (a bit of putrid ma- 

 terial) come in contact with the mortified part. This explains why, 

 though circumscribed gangrene of the lungs may be produced by 

 haemorrhagic infarction in disease of the heart, through obstruction of 

 the nutrient arteries (the bronchial arteries), it is that such a result is 

 far more common in metastatic infarction, caused by an embolus from 

 some region where putrefaction is going on. 



Diffuse pulmonary gangrene arises, in rare instances, during the 

 culminating period of pneumonia, the inflammatory stasis causing the 

 absolute arrest, both of circulation and nutrition, in the inflamed region. 

 Such an occurrence is the more likely when stagnation of the blood in 

 the capillaries causes coagulation of that which is in the bronchial 

 arteries. 



Pneumonia caused by entrance into the air-passages ot tood, or the 

 residua of food, is especially prone to run into gangrene, owing to the 

 putrefaction of these foreign bodies. 



Gangrene may also arise with or without previous inflammation, 

 from corrosion of the tissues surrounding a diffuse or saccular bronchi- 

 ectasis, and their implication in the putrefaction of its contents. 



It is difficult to explain the occurrence of diffuse gangrene of the 

 .ungs in drunkards, and in persons whose constitution has been much 



