This section is from the book "The Home Hand-Book of Domestic Hygiene and Rational Medicine. Volume 2.", by J. H. Kellogg, M.D.. Also available from Amazon: The Home Hand-Book of Domestic Hygiene and Rational Medicine, Volume 2.
Patient feels as though "something had burst " in his chest; very difficult breathing; patient lies upon the affected side, or sits up; severe pain in the region of the lower ribs; intercostal spaces obliterated on the affected side; when on left side, displacement of the heart to the right side; if on right side, displacement of the liver downward; unnatural resonance of the chest; usually, also, fluid, which changes position with change in position of patient; absence of natural breathing sounds; splashing sounds heard by placing the ear to the chest and shaking the patient quickly.
In this disease, one of the cavities of the chest is filled with air, the lung being in a state of collapse. The cause of the disease is perforation of the lung, which may result either from accident, as from a wound by a bullet, knife, or bayonet, or it may be the result of breaking down of portions of the lung, as in emphysema and consumption. With each active inspiration the air passes through the opening in the lung into the pleural cavity, and, as the opening is generally ragged, so that the air cannot escape during expiration, the quantity of air increases with each breath, until the pressure within the cavity becomes so great as to equal the force of an inspiration. Sometimes, in case of wounds, the lung cavity is connected with the connective tissue spaces, and the air penetrates the tissues of the chest and trunk, causing, in some instances, enormous bloating. The lung on the affected side is, of course, completely compressed, so that no air can enter it. Much pressure is also exerted on the lung on the strong side, caused by the expansion of the affected cavity. When the perforation occurs on the left side, the heart is crowded over to the right. We have met instances in which the apex beat of the heart, which is usually felt just beneath the nipple, was displaced, by the pressure of air in the left cavity, to the extreme right side of the breast-bone. Within a day or two after perforation occurs, pleurisy is usually set up, which occasions the exudation by which the cavity is gradually filled, in some instances, completely. We recently had under treatment a case of this character, which, owing to the complete filling of the chest with liquid, had been pronounced by a prominent professor in a medical college to be a case of fibrous growth in the chest. We pronounced the case one of empyema, and proved the diagnosis by performing the operation of aspiration and removing several quarts of pus.