SECTION III. 

 DISEASES OF THE PARENCHYMA OF THE LUNQ 



CHAPTER I. - 



HYPERTROPHY OP THE LUNG. 



IN by far the greater number of cases in which the lungs appear t<j 

 be enlarged, their tissue, instead of being hypertrophied, is atrophied 

 and wasted or rarefied, to use a customary expression. Under the 

 title of emphysema, we shall treat more fully upon this form of enlarge/ 

 ment of the lungs in the third chapter. 



Rokitansky describes an enlargement of the lung with simultaneous 

 increase of tissue, as true pulmonary hypertrophy. This is said to occur 

 as a vicarious development of one lung, when the other has been totally 

 destroyed. Here the walls of the vesicles are said to be thicker and 

 more voluminous, then- capillaries multiplied, and their tissue more resist- 

 ing, while the vesicles themselves are dilated. 



A second form of hypertrophy of the lung, which Skoda describes, 

 and Virchow calls pigmentary induration, consists in an increased vol- 

 ume of the pulmonary tissue, at the expense of the air-vesicles. We 

 notice it in severe chronic hypersemia of the lung, particularly in valvu- 

 lar disease of the mitral valve, and in hypertrophy of the right side of the 

 heart Here, too, the walls of the vesicles are thickened and then: ele- 

 ments multiplied, so that, as the lung has not grown larger, the vesicles 

 must seem smaller, and the tissues closer and more resistant. The color 

 of the tissue is darker and browner, and we notice numerous blackish 

 specks in it This coloring is due to capillary hsemorrhages in the tis- 

 sues, resulting from the intense engorgement, the pigment which pro- 

 ceeds from transformed haematin admitting of demonstration under the 

 microscope in the form of brownish and blackish granules, in the inter- 

 stitial tissues and in the epithelium of the air-vesicles. 



Either form of hypertrophy of the lung may be suspected to exist 

 during life, but neither ever admits of any certain diagnosis. 





