tt^MORRHAGIC INFARCTION OF THE LUNG. 157 



3iore boldly should we order opium. Let a Dover's powder be taken 

 at night, and during the day an emulsion, with half a drachm of lauda- 

 num, or half a grain of morphine. 3 



CHAPTER VII. 



PULMONARY HAEMORRHAGE WITHOUT LACERATION" OF THE PAREN- 

 CHYMA HAEMORRHAGIC INFARCTION METASTASIS TO THE LUNGS. 



IN former editions of my text-book I have treated of pulmonary 

 haemorrhagic infarction, which occurs from disease of the heart, and the 

 so-called metastatic infarction in separate chapters, since, notwithstand- 

 ing the complete identity in their essential anatomical lesions, the differ- 

 ence in their extent and seat, and, above all, the different manner in which 

 they originate, seemed to me to demand it. But from an opinion of Roki- 

 tansky, from an excellent essay by Gferhardt, and especially owing to a 

 series of observations of my own, published in the dissertation of Doctor 

 Hopf? I have become satisfied that my former views were erroneous ; 

 that the variations in magnitude and in the seat (neither of which are 

 constant) constitute no real difference, and that the modes of origin of 

 haemorrhagic infarction in heart-disease, and of that of metastatic infarc- 

 tion from thrombosis of a vein, or from external suppuration, or sanious 

 ulceration, are identical. 



ETIOLOGY. Haemorrhagic infarction consists in a capillary haemor- 

 rhage, confined to a small and sharply-defined section of the lung, and 

 often bounded by the limits of a single lobule. The blood is effused, 

 partly within the cavity of the vesicles and terminal bronchi, and partly 

 lies in their interstices between the fibres of elastic tissue by which the 

 air-cells are entwined. The haemorrhage does not produce laceration 

 of the lung-substance. The abrupt boundary of a haemorrhagic infarction 

 is caused by the fact that the bleeding only comes from the capillaries 

 pertaining to a single twig of the pulmonary artery. The range of the 

 capillary system of an artery depends upon its size ; hence haemorrhagic 

 infarctions which arise within the capillary limit of a large branch of the 

 pulmonary artery are far more extensive than one which forms about a 

 smaller twig. As the main trunks of the pulmonary artery enter the 

 roots of the lung in company with the great bronchi, and ramify toward 

 the surface, constantly growing smaller by repeated subdivision until 

 each ultimate twig terminates in a single lobule, the reason is plain why 

 the infarctions occurring in the interior of the lung are large, and why 



* Zur Diagnose des HaBmonhagischen Infarctes. Inaugural Dissertation voc 

 Di Flopf. Tubingen, 1865. 



