170 DISEASES OF THE PARENCHYMA OF THE LUNG. 



3. The termination of croupous pneumonia in cheesy infiltration (or, 

 as it is still too often called, tuberculous infiltration) is more common, 

 ff, in the second or third stage of the disease, when the fibrinous effu- 

 sion and the cells which fill the vesicles take on fatty degeneration, the 

 supply of serum effused by the walls of the vesicles prove insufficient, 

 the fatty masses begin to dry up before their liquefaction is completed, 

 and are converted into a more or less firm, yellow, cheesy substance. 

 Hereafter we shall again refer to the subsequent changes occurring in 

 this caseous infiltration of the lung, and shall express ourselves upon 

 the inexpedience of permitting the imputation to arise of a sort of iden- 

 tity of the products of the latter process with those of tubercular granu- 

 lation, by applying a similar title to both. 8 



4. Cirrhosis of the lung, or induration, is finally to be mentioned 

 as a rare termination of tedious pneumonia. This sequel is due to par- 

 ticipation of the vesicular walls and the interstitial tissue in the process, 

 when the disease is of long standing. Of this we shall treat more in 

 detail in Chapter XI. 



That portion of the lung which is not attacked by the inflammation 

 is the seat of intense hypergemia, as before stated ; in fact, pulmonary 

 oedema is, in many cases, the actual cause of death. Wherever the in- 

 flammation extends to the periphery of the lung the pleura also becomes 

 implicated, showing minute arborescent injection and ecchymosis. It is 

 then clouded and opaque, flabby, and covered with a thin layer of fibrin. 

 Generally, the right side of the heart, from which the outflow of blood 

 has been impeded by the stasis of the capillaries of the lungs, is over- 

 flowing with blood ; the left heart, its supply being abnormally dimin- 

 ished, is less full. In like manner, and for the same reasons, stagnation of 

 blood exists in the jugular veins, in the sinuses of the brain, and in the 

 liver and kidney. The condition of the blood is exceedingly striking. 

 The major part of that which is in the great vessels is not liquid, but 

 is coagulated into firm yellow masses. Lumps of curdled fibrin exist in 

 the heart, where they are firmly entangled amid the trabeculse and under 

 the valves ; and long, firm, tough, polypous coagula may be drawn out 

 of all the arteries. 



SYMPTOMS AND COURSE. We shall discuss the subject of secondary 

 pneumonia in treating of typhus, etc., as it is impossible to draw up a 

 picture of this disorder without making a detailed analysis of the symp- 

 toms of the disease upon which it depends. 



The commencement of primary pneumonia, in almost all cases, is 

 announced by a rigor which may last for half an hour, or even for sev- 

 eral hours, before giving place to a sensation of heat. As is well 

 known, the cold is a mere subjective symptom, and the temperature is 

 appreciably elevated, even during the algid stage. 



