The portion of the lung thus affected is usually within the lower or middle lobe, the upper portion being rarely involved. In the _second_, or _circumscribed_ form, a portion of the lung, generally near the surface, presents a dark-colored, hard patch, varying in size from a quarter, to a half-dollar piece or more, often quite circular, and bounded all round by healthy lung. This circular hard patch, which resembles closely an eschar produced by caustic potash, may adhere or be easily detached. In the latter case, it generally leaves a cup-like cavity, the surface of which is firm, granular, with the blood-vessels and bronchial tubes closed, and with the surrounding lung more softened, but generally presenting marks of pleurisy, pneumonia, and bronchitis all combined, which may be looked upon as an effort of nature to isolate and detach the diseased mass. =Pulmonary Hæmorrhage=—_Hæmoptysis_. Discharge of blood from the lungs by coughing, may result from a variety of causes, among which may be mentioned: 1, mechanical shock or injury, as in falls or blows upon the chest; 2, inflammatory action within the lungs; 3, disease of the heart; 4, disease of the arteries; 5, tubercular deposition; 6, tubercular destruction, with ulceration of vessels. In the first instance the expectorated blood may be copious or slight, according to the severity of the injury. If death soon results, an examination of the lungs will disclose one or more of the bronchial tubes filled with blood, which has plainly arisen from a rupture of some of the capillaries of the bronchial mucous membrane. The blood discharged in many cases of the early stage of consumption, and in young females after the suppression or retention of the menstrual flow, is from the same source. Hæmorrhage from the lungs may also take place as a result of tubercular deposits. The presence of tubercular masses must necessarily produce more or less pressure on the adjoining vessels, interfering with the flow of the blood through the same, and thus inducing congestion, and even rupture of some of the capillary branches. Again, where tubercular masses have progressed to softening, and a cavity has been formed, the ulcerative process may open a large vessel, and death result in a few minutes from excessive hæmorrhage. A post-mortem will here show the cavity, as well as the bronchial tubes and trachea, filled with coagulated blood. The blood expectorated during the early stage of an attack of pneumonia, is never copious, consisting mainly of streaks of blood through the saliva, while at a later stage, from being more uniformly diffused, it gives the peculiar _rusty sputa_ characteristic of this disease. The post-mortem appearances have already been given under the head of _pneumonia_.