however, irregularly prominent and unsymmetrical, bulging here and there in correspondence with the enlargement within. If the emphysema becomes extensive on one side, and especially if on both, it elevates the ribs and gives to the whole chest a form nearly cylindrical. But this happens only to those who have long been subject to the disease. The intercostal spaces, in this disease, are elevated more than to retain their ordinary relation to the ribs. The intercostal tissues, being flexible, are pressed up to a level or more with the ribs. The appearance of the clavicle is almost effaced, the spaces above and below are so raised. It is proper here to remark, that the distention of the chest in emphysema is always comparatively moderate, and never attains to that degree which is common in pneumothorax.

The movement of the thorax in vesicular emphysema, is decidedly less than in health. The lung having lost its elasticity, and the vesicles during respiration, remaining distended with air, the thorax necessarily preserves nearly the position which it has immediately after inspiration. Its motion is very limited. This, however, gives rise, to some extent, to that peculiar motion of the abdominal viscera usually termed abdominal breathing.

The resonance on percussion is greater, in vesicular emphysema, than in health, from the fact, that the lung contains more air, and is permanently distended. With persons whose thoracic parietes are thin, the abnormal resonance is considerable; but, with corpulent persons, and especially with those whose advanced age has appreciably diminished the elasticity of the chest, a moderate degree of emphysema will not give much unusual clearness. Over the most dilated portion of the lung, the clearness is always the greatest. Occasionally, where the lung is extensively dilated, the resonance approaches, in degree, that produced by pneumothorax; but the sound, in the former case, is never so tympanitic as in the latter.

In regard to the sounds of respiration, both the healthy bronchial and the vesicular sound are diminished. Before the disease, however, has made much progress, and has not very much compressed the lung, the bronchial sound remains nearly normal; but, in that portion to which the disease has extended, the vesicular sound is completely destroyed. The vesicles, when once filled,

remaining inflated, of course, can give none of the ordinary sounds.

But the pathognomonic sign of emphysema, in one of its forms, when heard, is the emphysematous crackling sound. This is a rustling sound, which nothing but the condition of the lung existing in this disease can produce. It is never heard till the disease becomes severe. Indeed, it is probable, that vesicular emphysema, uncombined with interlobular, never gives rise to it, till numerous sacs are formed from the breaking of one cell into another. Be that as it may, the sound supposes a dry, hardened, and not very pliant condition of the membranes. It may even be, that it involves some inflammation of the parts affected.

PROGNOSIS. The prognosis, in simple vesicular emphysema, is favorable, so far as prolonged life is concerned. Persons seldom or never die of this disease, alone. Recovery, however, is hardly to be expected; and the danger lies in a complication with other and graver affections. Generally, the progress of the disease is slow and undisturbed. If, however, it happens to be suddenly developed, by the influence of some preceding acute disorder, there may be a partial, though there is seldom or never, a full return towards health.

TREATMENT.-But little treatment of vesicular emphysema is of any service. Sinapisms, applied between the shoulders posteriorly, and over the dorsal vertebræ may, by their stimulating power, afford some relief in a paroxysm of dyspnoea. The anti-spasmodic effect of the lobelia inflata, too, is favorable. It may be given in common tincture, in doses of twenty or thirty drops. I prefer, however, to combine it with cypripedium pubescens or scutellaria lateriflora. The compound wine tincture, according to the formula, may be given in dram doses, every two hours. To this preparation, twenty or thirty drops of chloric ether may be added, with a favorable anti-spasmodic effect. Opiates combined with nauseants, in sufficient doses to quiet the cough, have been recommended; but the effect of the simple nervines, in connection with the nauseants, is far preferable.

The moderation of the paroxysms is essentially all that should

be aimed at. We know of no means of eradicating the disease. Of course, if it is complicated with other difficulties which are remediable, those should be removed; and circumstances tending to aggravate it may be guarded against.

SECTION II.

INTERLOBULAR EMPHYSEMA.

PATHOLOGY.-The areolar tissue which binds the lobules to one another, is, in its normal state, quite dense and close; but, when inflated with air, it is capable of a good deal of expansion. It is, in this tissue, that the air is found in interlobular emphysema. When the disease is slight, such of the affected parts as are visible on the surface of the lung, appear as little bubbles of air, arranged like beads upon a thread. In extreme cases, however, the lobules are widely separated by the effused air,-the partitions being sometimes, even one inch in breadth. These partitions are broadest towards the surface of the lung, and narrowest in the deepest-seated portions. Indeed, they show an arrangement somewhat like the section of an orange in which the septa radiate and diverge from a centre.

In this form of emphysema, it is common for bullæ to form on the surface of the lung, by means of air in the subserous areolar tissue, that is, the tissue which connects the pleura with the pulmonary parenchyma. These bullæ may be distinguished from the bladder-like prominences which appear there in vesicular emphysema, and which are dilated vesicles. The former are moved hither and thither, under pressure; the latter are stationary. This sub-pleural effusion of air is sometimes very great. The bullæ are said, sometimes, to equal a hen's egg in size, or even to be larger. "Bouillaud," says Dr. Watson, "mentions a case in which the bladder or pouch was equal to the size of a stomach of ordinary dimensions."

The contents of these sacs are supplied from the air passages, doubtless by the rupture of some of the superficial vesicles. Suppose then, such sub-pleural collections of air, and suppose that, under the pressure, the pleura gives way. The immediate conse

quence is pneumo-thorax, complicating the emphysema; and this condition of things sometimes, though not often, occurs.

In severe cases of interlobular emphysema, the air readily passes to the areolar tissue of the mediastinum, and thence to the subcutaneous areolar tissue of the neck and chest. In such a case, we have not merely pulmonary emphysema, but emphysema, in a more enlarged sense.

Between vesicular emphysema, and interlobular, there is an important difference in the circumstances of their formation. The former is slowly and gradually established; the latter, suddenly. The permanent dilatation of the vesicles requires time; and they lose their elasticity and break into one another only by degrees. The interlobular effusion of air, on the contrary, may be effected in a few minutes, or even seconds. It is produced by some violence. A woman may so exert herself in childbirth, or a man in lifting some heavy body, that, as a deep inspiration is taken and the glottis is voluntarily closed, some rupture takes place, opening a vesicle or vesicles into the areolar tissue.

DIAGNOSIS. The general and the physical signs of this form of emphysema are mostly the same as those of the vesicular. The emphysematous crackling, however, is much more extensive and perfect, in this form than in the other. The dyspnea, too, the distention of a portion of the chest, and the resonance on the percussion of that portion may be greater. But the suddenness with which interlobular emphysema is developed, and the graver character which it assumes, afford the principal means of discriminating it.

PROGNOSIS. The prognosis in this case is very different from that in the other. Under favorable circumstances, the newly developed disease will sometimes cure itself. The rupture, probably under the influence of inflammation and the subsequent granulating process, closes over, and the effused air is absorbed. If, however, this does not soon take place, or if the opening is reestablished and remains, the disease is generally, soon fatal.

TREATMENT.-But little can be done directly to aid the process

of cure, if it takes place. Equalizing the circulation and quieting the nervous system, so as to allow the reparative process to go on uninterrupted, will be of service. If the disease is terminating fatally, the means of palliating it, or relieving the urgent symptoms, are the same as recommended for vesicular emphy

sema.

CHAPTER VII.

PULMONARY CONGESTION.

PATHOLOGY.-This is an abnormal fullness of the blood-vessels of the lungs, which are situated anatomically between the right and the left side of the heart. It is produced, sometimes by general and sometimes by local causes. When the right ventricle of the heart throws more blood into the lungs, than the left ventricle throws over the system, that is, away from the lungs, there must necessarily be an accumulation, and we speak of the lungs as congested. This difficulty arises from various causes. Coughing in pertussis or in severe bronchitis, may arrest, for a time, the circulation in the lungs. Running, straining, or any violent execution, by which the person is put out of breath may do the same.

But disordered nervous action will frequently produce a less temporary congestion of the lungs. This remark is applicable to both sexes, though it is mainly illustrated in the case of nervous and hysterical females. Taking cold at the menstrual period, habitual amenorrhoea, or almost any disturbance of uterine action, with some constitutions, will be sufficient to develop pulmonary congestion.

There are two very different conditions under which this congestion occurs. One is with females who are of sanguine temperament and plethoric habit, with whom the congestion is of the active kind. The other is with those whose tendency is towards anæmia or chlorosis,-whose blood lacks corpuscles, or corpuscles and fibrine, and with whom the congestion, when it occurs, is of the passive kind.