cratic method of succussion is useful. The mode of procedure is simple. The patient is placed in a sitting posture, and while the body is quickly though moderately shaken by applying the hands upon his shoulders, the agitation of the fluid thus produced, is very clearly heard.

Another morbid sound heard in this disease, is the amphoric respiration, that buzzing sound caused on blowing into a bottle. The cavity of the pleura may be compared to the bottle, and the perforation of the pleura, to the opening into it. As soon as the pleural sac becomes somewhat distended with pus, the amphoric respiration ceases, or if the opening is covered with false membrane, so as to prevent the exit of air from the cavity, after having entered it in inspiration, the amphoric sound is not heard, and there is either no morbid sound, or a slight bronchial respiration.

Attendant upon the amphoric respiration is a corresponding resonance of the voice, which follows the same course and ceases at the same time.

As pneumothorax passes into empyema, the physical signs decline, and there is then dullness on percussion, with almost entire absence of the respiratory murmur. The accumulation of pus is then much greater than in ordinary cases of pleurisy, sometimes amounting to several gallons, causing extreme difficulty of breathing.

By the general symptoms of pneumothorax, certainty cannot be obtained in diagnosis. With the physical signs, however, there is no difficulty in detecting the nature of the lesion. These are not only pathognomonic of the existence of the disease under consideration, but they go farther, and enable us to point out its different stages, its degrees of severity, and its gradual passage into empyema.

PROGNOSIS. The prognosis is generally unfavorable. In general, it is speedily fatal. But this result depends as much upon the disease which causes the pneumothorax, as upon the degree of the existing lesion. In case one lung is affected by tubercular disease, or in any way prevented from performing its functions, and the healthy lung is so perforated as to produce on that side, pneumothorax, the effect is necessarily fatal. In such a case the

patient dies in a few hours or days, from exhaustion and orthopnoea.

In forming the prognosis, therefore, the condition of the lung, not the seat of perforation, should be made an object of special study. If one lung is healthy it may carry on the functions of both. Whenever, then, we have one healthy lung and the other is not the location of tuberculous disease, the prognosis is more favorable. But if the diseased lung is tuberculous, although the other is comparatively healthy, the probability of recovery is small, for the phthisical disease soon extends to the healthy lung, and destroys it. If the pleura is completely filled with pus, the effect is to develop hectic fever, and therefore the physical condition is worse than when the pleural sac is filled with air alone. Under the most favorable circumstances, we should consider the prognosis uncertain, and in those cases complicated with phthisis, there is no hope of a cure.

Pneumothorax has no fixed period of duration. In a short time it may prove fatal. Dr. Gerhard relates one case in which death took place in less than an hour, and two other cases in which life was prolonged until the lapse of fifteen or eighteen months. In one of these latter cases, the patient made two long voyages, and, according to his own statement, did full duty as a seaman while his pleura was enormously distended with pus.

TREATMENT. The means which art is able to employ in the cure of this disease, are limited. There are, however, certain general indications to fulfill, a knowledge of which is serviceable to the practitioner. If the pain is severe and if dependent upon a perforation of the pleura with inflammation of that membrane, local means, such as warm fomentations, or sinapisms applied over the painful region may be employed with advantage. The degree to which general relaxants should be carried must be proportionate to the intensity of the symptoms. Some preparation of lobelia, or the employment of some other diaphoretic and sedative agent administered according to the necessities of the case, will be useful to allay inflammation.

Cough preparations sometimes are useful. In cases in which there is but little hope of permanent relief from medicine, and in

which other nervines are not found sufficiently potent to allay pain, opiates should be given to quiet the system, and procure sleep. If pneumothorax caused by a wound, should suddenly arise in a strong and vigorous constitution, the most active relaxants in the materia medica should be immediately employed in order to keep down the inflammation.

To prevent febrile excitement, and to promote absorption of effused liquids, those means should be used which, in the article on Chronic Pleuritis, are recommended. To sustain the strength, the most efficient tonics and nutritive diet, should also be used. In case these do not have any good effect in consequence of the disease of the digestive functions, gentle emetics should be occasionally prescribed.

If remedies fail to prove at all salutary, and the disease should threaten immediate suffocation from the quantity of air and liquids in the pleural sac, the gas and liquid should be evacuated by the operation for empyema. Experience proves, that, under certain circumstances, the opening of the chest, may be made with a good effect. Successful cases are reported by Laennec, by Riolan and Ponteau. In case the opening is made without the admission of air, the disease under favorable circumstances admits of cure.

[The operation, according to Dr. Gerhard, is allowable when the object is to favor the escape of gas, or the pus which is afterwards secreted. Immediately after the perforation of the pleura, the dyspnoea may suddenly become so great that immediate death is to be feared. The side may be punctured in the usual manner, and the gas be allowed to escape; but, as in this case, the subsequent dangers of the disease are certainly increased by exposing the cavity of the pleura so freely to the air, the operation cannot be justified except it be a measure of absolute necessity; at best, it relieves the patient only for a short time. In the cases of advanced empyema which follow pneumothorax, paracentesis may be performed when the oppression is extreme, and the intercostal spaces are much bulged out. The operation is, however, very far from being devoid of danger; for the free entrance of the air into the cavity, tends to increse the inflammation, and to aggravate the hectic fever. The usual precautions should be carefully attended to after the operation.

If it be thought advisable to perforate the chest, the best mode is perhaps the one perforined by Dr. Bowditch of Boston, who states that he has several times performed the operation without difficulty, or subsequent suffering to the patient. He uses a very small trocar, and allows the fluid to flow through it; the instrument is too small to allow of the entrance of any notable quantity of air, and in that manner all mischievous results from the operation are prevented.]

CHAPTER XIII.

HYDROTHORAX.

Although generally applied at present exclusively to dropsical collections in the pleura, the term hydrothorax, may from its origin-udwp, water, and pağ, chest,-be applied to any case of serous effusion within the cavity of the chest. In this cavity three kinds of dropsy may exist. In the first place, there may be dropsy of the parenchyma of the lungs, called pulmonary edema; secondly, dropsy in the pleural sac, and thirdly, dropsy of the pericardium. The former of these varieties is already treated of; the latter will be considered when I treat of diseases of the heart. Only of that serous effusion, therefore, which distends the pleural cavity, I shall speak in this place.

PATHOLOGY.-The pathology of the pleural variety of hydrothorax, is, in some respects, similar to that of chronic pleurisy. The liquid effusion, however, is serous and not purulent. In color it is more frequently yellowish or brownish, and sometimes is tinged with blood. The pleura is not, in many cases diseased and in this respect, it differs from chronic pleurisy. It is apt to be associated with tubercles in their earlier stages of development. Like other forms of dropsy the effusion often depends upon inflammation of the secreting membrane. Some authors consider the effusion arising from this cause as distinct from dropsy; but they fail to assign a good reason for the distinction. Whatever is its origin, when the effusion is serous in its character,

it must be considered dropsical. A very reasonable explanation of the phenomenon is, that the pleural membrane is irritated, and that the congestion of the blood-vessels, is relieved by the serous effusion, before the inflaminatory process is far advanced.

In the pleural sac more or less serous fluid after death is frequently found, which, during life had caused but little disturbance. This may be the result of effusion in the dying state, or of chemical changes occurring after death. To constitute dropsy the effusion must be sufficient to derange in some degree the functions of life. Whenever existing in this manner, it causes extreme difficulty of breathing, always increased by exertion, by walking, running or ascending heights, or by the horizontal posture.

DIAGNOSIS.-General symptoms. When the effusion is small, the dyspnoea is not great, but as fluid collects, the difficulty of breathing increases. In general, the patient lies on the side affected, and is most comfortable when the shoulders and chest are elevated.

In the advanced stage the horizontal position causes great suffocation, from the tendency of the fluid when the patient lies down, to impede the pulmonary functions. Sometimes placing the patient, during a few moments on his back, may cause sudden death. Preceding such a result, there are a livid or purplish hue of the face, and an almost black appearance of the lips, caused by a deficient oxydation of the blood.

In many cases, it is associated with other forms of dropsy. Anasarca, dropsical swelling of the eye lids, especially in the morning, and in the evening dematous swelling of the feet, frequently accompany it through most of its progressive changes.

Special symptoms. The affected side is dilated so much in some cases, as to be apparent to the eye, and easily known. by measurement of the corresponding parts of the chest on opposite sides. The heart, mediastinum, diaphragm, in fine, all adjacent organs, are more or less displaced when the effusion is very copious. The intercostal spaces are bulging, and the ribs farther separated than natural. By succussion, a splashing sound may sometimes be produced. The vibrations of the chest caused by