This is commonly called lung fever. It is characterized by inflammation of the parenchyma or texture of the lungs. The patient is generally found lying on his back, complains of pain in his side, has more or less difficulty of breathing, a cough at first dry, but soon accompanied by bloody phlegm. As the disease becomes severe, the phlegm becomes very tenacious, so that it will adhere to the spit-cup if turned upside down. Three characteristic stages are observed in this disease, viz., congestion, hepatization, and softening. In the first stage the lungs become engorged with blood or congested, and if the lungs are percussed a dull sound is elicited, and if the ears are applied to the chest a minute crackling sound is heard, similar to that produced by rubbing fine hair between the fingers and thumb. It is only heard during inspiration, and is caused by the air breaking up the mucous adhesions. The urine is scanty and high colored. In the second stage the lungs become solid, or hepatized, resembling the liver. Some writers call it red softening. The dulness becomes more distinct upon percussion, and a whistling sound is heard if the ear is placed to the chest. The cough is more or less dry, but the fever is aggravated. There is great prostration, restlessness, complete loss of appetite, constipation, a loaded brown tongue, and the respiration is hurried and imperfect. In the third stage the lung softens and becomes filled with matter, and portions of the lung are apt to give way. The cavities may be detected by increased resonance at some parts by percussion, and the cavernous breathing by auscultation. There is also a metallic tinkling heard, and the sputum becomes more liquid, looking like prune-juice, and the general condition of the patient worse in every respect. If the disease advancs into this stage, recovery is not very probable.

Pneumonia may be double or single; the right lung suffers, however, more frequently than the left. If pleurisy is associated with it, it is called pleuro-pneumonia. When characterized by great debility and prostration, and is of a low type, it is called typhoid pneumonia. The pneumonia of children is called lobular, as it is generally confined to one or two lobes of the lung.

TREATMENT. -- Bleeding formerly was done in each case, and is again receiving attention by some physicians, but I deem it injudicious, as a general thing, though it may be of benefit in some plethoric cases. The treatment should be commenced with a mild cathartic, and the fever should be controlled with veratrum. The expectorants should be administered, and in cases of great prostration, beef-tea and alcoholic stimulants must be given. The chest should be blistered, and a cloth smeared with lard should be placed on the raw surface. Sleep should be promoted by lumulin or the opiates, and if great difficulty of breathing exists, turpentine should be poured on hot water, and the patient allowed to breathe the vapor. Fresh air, quietude, and rest, with frequent sponging of the body with tepid water, should not be neglected.