194 DISEASES OF THE PARENCHYMA OF THE LUNG. 



upon trie progress of the disease. On the other hand, it is better not 

 to employ cutaneous irritants, whether sinapisms or blisters, at all, or at 

 least not until a late period, when resolution is going on too slowly. 

 Finally, if the patient be plagued by cough or restlessness, or by sleep- 

 less nights, the indicatio symptomatica may require the use of narcotics, 

 and we must not fear to administer a Dover's powder at night under 

 these circumstances, notwithstanding the persistence of the fever. 



CHAPTER X. 



CATARRHAL PNEUMONIA BRONCHOPNEUMONIA. 



ETIOLOGY. The catarrhal process is a form of disease peculiar to 

 the mucous membranes, and, as no mucous membrane with mucous 

 glands exists in the pulmonary vesicles, the name catarrhal pneumonia 

 is not quite applicable to the disease in question. Nevertheless, as 

 catarrhal pneumonia never arises unless preceded by catarrhal bron- 

 chitis, and as its characteristic pathological alterations are entirely 

 analogous to those of bronchial catarrh, we shall retain the generally 

 adopted title. In many cases catarrhal pneumonia arises solely through 

 the extension of the morbid process from the bronchial mucous mem- 

 brane into the air vesicles. In the great majority of instances, how 

 3ver, this disease develops in pulmonary tissue which has already col- 

 lapsed, a circumstance which makes it more than probable that col- 

 lapse of the air-cells essentially favors its occurrence. It is not sur- 

 prising, moreover, that the capillaries of the alveolar wall, when lib- 

 erated from the pressure of the air enclosed in the vesicles, should be- 

 come enlarged and surcharged with blood, nor that after long persist- 

 ence of this capillary hyperaemia, it should be attended by augmented 

 transudation and copious cell-formation. Now these are the very 

 alterations which the anatomical appearances of catarrhal pneumonia 

 present. 



This disease is most commonly observed as a complication of 

 measles, and of whooping-cough ; but the reason for this seems to be 

 simply, that capillary bronchitis occurs much more frequently in the 

 course of the latter complaints than in healthy children. Causes of 

 catarrhal pneumonia, other than those from which capillary bronchitis 

 and collapse of the lung originate, are unknown. We may very 

 properly call it a disease of childhood, as it is in children that capil- 

 lary bronchitis, and its sequel, partial pulmonary collapse the pre- 

 cursors and initial stages, as it were, of catarrhal pueumonia are most 

 commonly seen. 



ANATOMICAL APPEARANCES. While croupous pneumonia extends, 



