138 DISEASES OF THE PARENCHYMA OF THE LUNG. 



it does not pit on pressure ; after longer duration, the parenchyma has 

 lost its elasticity, and the lung retains the impression of the finger 

 longer and more distinctly. If the cedema be consequent upon an in- 

 tense hyperaemia, the cedematous lung is colored red, but, if it be one of 

 the symptoms of a general dropsy, it may appear quite pale. If we cut 

 into the cedematous spots, an enormous quantity of liquid, sometimes 

 clear, at others of a red color, mixed more or less with blood, flows over 

 the surface of the cut. This liquid is full of bubbles, frothy, and copi- 

 ously mixed with air, if the air-cells have not been entirely filled up 

 with serum and still contain air. In other cases, the liquid hardly con- 

 tains any bubbles, except a few from the larger bronchi. Here the serum 

 has expelled all the air from the vesicles. In cases of hypostasis we 

 find the same conditions ; intense hyperaamia, amounting to splenifica- 

 tion, or a more or less complete cedema, uniformly occupying the poste- 

 rior portion of the lungs next the vertebrae. If the patient have lain 

 continually upon one or other side, the hypostasis is often confined to 

 this side alone, and may be very extensive, while the other lung may 

 be healthy. If the contents of the air-vesicles at the condensed portions 

 of the parenchyma cannot be completely evacuated by pressure, if the 

 section shows an indistinct granular aspect, if the liquid which flows out 

 be clouded by little coagula of fibrin, we have the so-called hypostatic 

 pneumonia before us. 



SYMPTOMS AND COTTKSE. A moderate degree of fluxion to the 

 lungs presents no symptoms. The dilated capillaries present a greater 

 surface to the air, the circulation is accelerated, and with this accelera- 

 tion the change of the blood in the lung grows more brisk, as both cir- 

 cumstances promote and facilitate oxygenation. When, however, the 

 fluxion is more considerable, the enlargement of the dense capillary net 

 and the swelling of the cell-walls from augmented transudation may 

 diminish the capacity of the air-vesicle. An obstacle to respiration is 

 thus set up. The lungs cannot inhale so much air. Those narrow- 

 chested youths and girls, of whom we have spoken, in their attacks of 

 palpitation, complain of shortness of breath, nay, they very correctly 

 call the sensation which they experience in the chest a " fulness " or 

 " stricture." A short, dry cough is added to this condition ; far more 

 rarely a frothy expectoration, with scattered streaks of blood. There is 

 no pain in the chest. Physical examination shows no abnormities. 

 We may as well state here that " habitual determination of blood to the 

 chest" is sometimes the forerunner of consumption, though perhaps not 

 as often as we are apt to believe. 



The violent hyperaemia of the lungs, mentioned in the pathogeny, 

 and which must be regarded as consequent upon excessive action of the 

 heart, sometimes aiises rapidly, and threatens life with unexpected sud- 



