206 DISEASES OF THE PARENCHYMA OF THE LUNG. 



DIAGNOSIS. It is often by no means easy to distinguish a diminu- 

 tion and consolidation of the lung, resulting from interstitial pneu- 

 monia, from a similar condition arising from continued compression. 

 The thoracic wall sinks in after either process, and the heart, liver, and 

 spleen are displaced, so that the history of the case is often our sole 

 guide. If it cannot be determined whether the primary disease have 

 been pleurisy or pneumonia, the question often remains unsolved, al- 

 though bronchiectasis is far oftener a consequence of interstitial pneu- 

 monia than of compression of the lung. 



In distinguishing bronchiectatic caverns from tuberculous excava- 

 tions, besides the difference of their situation, the following points are 

 to be taken into consideration: 1. Patients with .bronchiectasis are 

 generally free from fever, and hence often long retain a tolerable de- 

 gree of strength, and suffer but little emaciation. 2. Secondary dis- 

 ease of the larynx and intestine is of rare occurrence in cases of bron- 

 chial dilatation; hence, hoarseness and diarrhoea, in a doubtful case, 

 would indicate the tuberculous nature of the disease, although the 

 coexistence of bronchiectasis is by no means excluded. 3. Saccular 

 dilatation of the bronchi is so often accompanied by emphysema that, 

 in forming a differential diagnosis between bronchiectasis and tuber- 

 cular excavation, the evidence of the existence of emphysema would 

 turn the scale in favor of the former. 



PROGNOSIS. As interstitial pneumonia scarcely ever is an inde- 

 pendent affection, the prognosis depends essentially upon the original 

 disease. This is especially the case when the malady accompanies 

 tuberculosis. Extensive wasting of the lung, consequent upon tedious 

 pneumonia, or accompanying chronic bronchial catarrh and emphysema, 

 is often endured for a long time, even after bronchiectatic cavities 

 have formed, the patients only succumbing at a late period, upon the 

 establishment of marasmus and dropsy. At other times, life is sud- 

 denly endangered by haemorrhage from the walls of the caverns, or by 

 pneumonia from diffuse putrescence of the lung. 



TREATMENT. In the stage at which interstitial pneumonia becomes 

 recognizable, it is as impossible to do any thing for its relief as it is to 

 soften and resolve any other form of cicatricial tissue. We are equally 

 powerless to effect the closure and obliteration of bronchiectatic vomicae. 

 It only remains, therefore, for us to see to the emptying of these cavities, 

 so that the foul secretion may not occasion still greater corrosion of 

 the bronchial walls or parenchyma of the lungs. As a second indica- 

 tion, we must endeavor to limit the secretion, both of the cavity itself 

 and of the bronchi, from which secretion seems to flow into the cavity. 

 Both indications are best met by the inhalation of oil of turpentine, as 

 re<x>mmended above. It has already been mentioned that this pro- 



