The loss of weight, with the continuance of the disease, is not marked, as it usually is in cases of pulmonary tuberculosis. The patient usually does not present pallor or a notably morbid aspect.

More or less cough always exists. In frequency and severity this symptom varies much in different cases. It is paroxysmal, violent, and difficult in proportion to the small quantity and tenacity of liquid products within the affected tubes. The expectoration also varies much in different cases. It is sometimes abundant, consisting of mucus with serous transudation. When the latter is copious, the affection has been called bronchorrhoea. It may consist of large, solid, greenish or ash-colored sputa, and in some cases small pearl-like masses are raised after much coughing. The sputa may at times be streaked with blood. In general, the expectoration is muco-purulent, the purulent characters not unfrequently predominating, and sometimes it appears to consist of pure pus. Formerly it was thought to be highly important to determine whether the expectoration was purulent or not, the presence of pus being supposed to denote something more than bronchitis. This is now deemed a point of comparatively little importance, since it is ascertained that pus may be formed on a mucous surface. A very copious expectoration of pure pus, however, does point to some other source than bronchitis, such as the discharge of a tuberculous abscess, the third stage of pneumonitis, abscess of liver evacuating through the lung, empyema with perforation, etc. The diversified characters which belong to the expectoration in different forms of disease are of less value in a diagnostic view than was formerly supposed, since the knowledge which has been acquired of physical signs furnishes a far more reliable source of information respecting intra-thoracic conditions.

Chronic bronchitis, of course, involves the same causes as the acute in the cases in which it is preceded by the latter. It may be produced and maintained by the inhalation of irritating particles of stone or metal in the exercise of certain occupations. It is supposed to be one of the varied local affections attributable to the syphilitic poison. Its continuance, in some cases, is referable to organic affections of the heart, consisting of obstructive or regurgitant mitral lesions. These act by inducing pulmonary congestion. It is an affection incidental to old age, occurring without any obvious causative agencies. It occurs in youth and middle age, irrespective of apparent causes, and is often associated with asthma and emphysema. To these affections it stands in the relation of a cause rather than an effect. In cold latitudes it is sometimes manifestly dependent on climatic causes, recurring with each successive winter, and disappearing during the summer season, or on removal to a warm climate.

It

It is not an affection which tends directly to destroy life. In the aged it may sometimes dispose to the development of capillary bronchitis, and thas, indirectly, prove serious. In connection with the feebleness of advanced years, it may lead to collapse of pulmonary lobules, and, in this way, shorten life. Its existence in a patient prostrated with any other disease involves danger from the accumulation of morbid products in the bronchial tubes, which may be the immediate cause of death by apnœa. may lead to the development of asthma and pulmonary emphysema, affections which, although not immediately dangerous, diminish the duration of life. Aside from these contingencies, the evil to be apprehended relates to the permanency of the affection. It is liable to become established, persisting for years, and, in aged persons, for the remainder of life. The existence of chronic bronchitis does not involve an increased liability to the development of pulmonary tuberculosis, but, perhaps, the reverse.

The diagnosis of chronic bronchitis involves discrimination from pulmonary

tuberculosis. This would be difficult, and, indeed, sometimes impossible, were the investigation to be limited to the symptoms; hence, before physical signs were studied, these two affections were of necessity confounded. The importance of making the discrimination is obvious in view of the great difference between the affections as regards prognosis. The differential diagnosis cannot be fully considered without anticipating the consideration of pulmonary tuberculosis. It will suffice to state that it is to be based mainly on the absence of the symptoms and signs which are diagnostic of the latter disease. In other words, it is concluded that pulmonary tuberculosis does not exist, from negative evidence, or reasoning by way of exclusion. The results of physical exploration, as just stated, are mainly to be relied upon, but the absence of symptoms which belong to the clinical history of tuberculosis, is also to be considered, such as progressive, marked emaciation, hæmoptysis, and accelerated breathing. These symptoms are wanting in chronic bronchitis. The physical signs in this variety of bronchitis are the same as in the acute form, viz., the dry and moist bronchial rales, the resonance on percussion and the vocal resonance unaffected, the respiratory murmur weakened and sometimes suppressed over a portion of the chest from temporary obstruction of bronchial tubes.

The coexistence of pulmonary emphysema is to be determined by symptoms and signs diagnostic of this affection, which will be considered hereafter.

In the treatment of chronic bronchitis bloodletting or other depletory measures are very rarely, if ever, indicated. The affection seldom exists under circumstances which render it desirable to lower the powers of life. Counter-irritation by means of croton oil, or stimulating liniments, is sometimes useful. The diet should be nutritious but not stimulating, consisting of milk, eggs, fowl, fish, and farinaceous articles. Meat, however, is not to be interdicted if the system be enfeebled. Wine and alcoholic stimulants are to be avoided, excepting when measures to support or strengthen the system are indicated. Attention to the surface of the body is important. In a cold climate woollen or silk garments should be worn next the skin. An undergarment of buckskin or chamois leather, worn over light woollen or silk, affords, during cold weather, great protection, and saves the inconvenience of an undue quantity of clothing. The object is to secure a uniform temperature of the surface, and maintain the functions of the skin.

Medicines may be employed with a view to palliation and cure. If cough be troublesome, exceeding the amount requisite for expectoration, soothing remedies are called for. Opium, however, is to be prescribed with circumspection, in the first place, lest the habit of using it be formed. This is a consideration to be taken into account in all chronic affections. And, in the second place, in feeble subjects, and under circumstances in which there may be danger from an accumulation in the bronchial tubes, serious consequences may sometimes follow the blunting of that sense of the presence of morbid products which leads to their removal by efforts of expectoration. Moreover, the use of opium tends to impair the digestive powers. For these reasons, other anodynes, such as hyoscyamus, conium, belladonna, and hydrocyanic acid, are generally to be preferred.

As a rule, the remedies which are given as expectorants are not indicated. The nauseant expectorants do harm by their depressing effect, and by disturbing the appetite and digestion. The stimulant expectorants, such as squill, senega, etc., are of doubtful efficacy, and, if not useful, are more or less hurtful.

Certain remedies, however, sometimes exert a curative effect. This is true of the balsam of copaiba. I have known this remedy to act almost as a specific; yet, in many cases, it has little or no effect. The iodide of potas

sium, also, in some cases is remarkably efficacious; but in other cases it is useless. The chlorate of potassa is sometimes a useful remedy. The muriate of ammonia is by some considered a valuable remedy. Other remedies which have been found serviceable are naphtha, sulphur, and cubebs.

Frequently marked benefit, as regards the bronchitis, is derived from tonic remedies in conjunction with measures to invigorate the system. The salts of quinia, and the preparations of iron are often highly useful. These and other tonic remedies are indicated if the powers of the system be reduced, or the patient be anæmic. A generous diet is to be conjoined, and wine or alcoholic stimulants may be taken moderately with advantage. Out-door life, in such cases, should be added. This plan of treatment is applicable to a. pretty large proportion of the cases of chronic bronchitis. To improve the general health, and restore vigor, are important objects in the treatment of this, as of any chronic local affection.

The inhalation of medicated vapor has, of late years, been revived, and, at = this moment, is a popular form of empiricism. Soothing remedies administered in this way are not without utility in certain cases. The vapor of warm water impregnated with opium or conium sometimes affords relief of cough and uncomfortable sensations within the chest. Breathing, from time to time, chloric ether or chloroform, with a few respirations, will sometimes prove very efficacious in palliating an irritable, teazing cough. Inhalations, with a view to a local curative action, are rarely beneficial, and are liable to aggravate the pulmonary symptoms. Chlorine, iodine, and tar vapor have been used for this purpose.

It is an object of treatment, in some cases, to diminish the amount of expectoration when this is excessive. For this end astringent remedies may be employed, such as tannic acid, the persulphate or pernitrate of iron, and the preparations of zinc. After a bronchitis, however, has become habitual, especially in the aged, it sometimes appears to be, as it were, an element of health. At all events, patients complain of the discomfort arising from the suspension or diminution of the expectoration, and, for this reason, opiates do not procure relief. Under these circumstances, expectorants are useful as palliatives.

Change of climate is sometimes advisable. A removal from a cold and variable climate, to a situation in which the temperature is mild and equable, may be attended with marked relief, and perhaps lead to recovery. Benefit may be looked for especially in the cases in which immunity from the disease or marked amelioration is experienced during the summer season. The trial of change of climate is particularly advisable in the cases in which emphysema is becoming developed in connection with the bronchitis.

CHAPTER VII.

Emphysema of the Lungs-Interlobular or Interstitial Emphysema-Subpleural Emphysema -Vesicular Emphysema or Dilatation of the Air-Cells-Anatomical Characters-Clinica History-Pathological Character-Causation-Diagnosis-Prognosis-Treatment-Asthma -Clinical History-Pathological Character Causation - Diagnosis-Prognosis-Treat

ment.

In the order of pulmonary diseases, emphysema and asthma naturally follow bronchitis, from the fact that they involve the latter disease in the great majority of cases. Emphysema, elsewhere than within the chest, denotes the

presence of air in the areolar or connective tissue. It may denote the same condition as applied to the lungs. A form of emphysema of the lungs consists in the extravasation of air into the areolar tissue which unites the pulmonary lobules. This is distinguished by the name of interlobular or interstitial emphysema. It arises from rupture of the air-cells, establishing a communication between the latter and the interlobular areolar tissue. The accumulation of air in this situation widens the interlobular spaces at the expense of the lobules, and thus diminishes their functional capacity. The air traversing the areolar tissue at the root of the lung may find its way into the subcutaneous areolar tissue of the neck, and become diffused over more or less of the entire body. This sometimes follows perforating wounds of the chest or injury of a lung by the extremity of a fractured rib. Another situation of the same form of emphysema is the subpleural areolar tissue. In this situation the air sometimes detaches the pleura so as to form air-blebs or tumors of greater or less size. These are not unfrequently found after death. They are occasionally quite large. I have seen a pleural air-tumor as large as an English walnut. Bouillaud has reported a case in which a tumor existed as large as the stomach. Of course, in proportion to their size, they interfere with the full expansion of the lung, and in this way interfere with the function of respiration. They are liable to rupture during life, and pneumothorax, with or without pleuritis, may thus be produced. Cases of pneumothorax, in which recovery takes place, probably exemplify this accident, and an instance, supposed to be of this kind, has been given in a preceding chapter.

By the term emphysema, however, as applied to the pulmonary organs, is generally meant an abnormal accumulation of air within the air-vesicles. To distinguish this from the other forms just noticed, it is called pulmonary or vesicular emphysema. It has also been called rarefaction of the lungs. As the accumulation of air is an effect of a morbid increase of the size of the cells, the simple term dilatation of the air-cells expresses correctly the pathological condition. This condition is to be understood as constituting the affection under consideration.

An emphysematous condition, limited to a few lobules, is frequently incidental to the deposit of tubercle, and occurs in various pathological connections. Under such circumstances, it is not entitled to be regarded as constituting an individual disease. In the latter sense, the term emphysema denotes a greater diffusion of this condition, and, as a rule, the affection is bilateral or symmetrical. Emphysema more or less diffused is sometimes called lobar, and it is called lobular when limited to comparatively a few lobules.

ANATOMICAL CHARACTERS.-As a rule, the lungs affected with lobar emphysema are increased in volume. They remain expanded when the chest is opened, not collapsing under atmospheric pressure, as they do in a healthy condition. Their contractility is thus impaired. They crepitate on pressure less than healthy lung. The cells are enlarged so as to be plainly visible through the serous covering with the naked eye in the superficial lobules. They may be dried without collapsing, and, on section, frequently present spaces varying in size from a pin's head to a bean, and sometimes much larger. These are produced by rupture of the intercellular septa and coalescence of more or less of the cells. In some specimens these cavities are so numerous and large that the affected organs resemble the lungs of the batrachian reptiles. According to Dr. Gairdner, traces of collapsed lobules may generally be found on careful examination. The enlargement of volume may be sufficient to cover the heart and depress it downward and forward

toward the epigastrium. The diaphragm may be flattened and depressed, pushing downward the organs situated beneath it. These changes denote emphysema existing in a great degree and extensively diffused. Existing in a less degree and not embracing all the lobules of the affected lobes, the emphysematous portions are distinguished by their prominence, dryness, and exsanguine appearance. The bronchial tubes are sometimes dilated. Evidence of coexisting bronchitis is generally present. The right side of the heart is usually dilated if the emphysema be extensive. The emphysema is rarely equal in the two lungs, and the predominance is usually on the left side. The upper lobes are much oftener affected, or affected to a greater extent, than the lower lobes, and the affection is more marked in the anterior than the posterior portion of these lobes.

In some cases the emphysematous condition appears to be due chiefly to destruction of the intercellular septa from atrophy, and the volume of the lungs is not much, if at all, increased. The emphysema in these cases is peculiar to aged persons, and has been distinguished as senile emphysema.

Emphysema, developed in a person free from tubercle, undoubtedly diminishes the liability to tuberculous disease. The two affections are rarely associated, exclusive of the cases in which pulmonary lobules in the vicinity of tuberculous deposits, become secondarily emphysematous. In these cases the emphysema is lobular. The condition of emphysema is, also, to some extent, incompatible with hæmoptysis. Pneumonitis, as a rule, is not developed in an emphysematous patient. I have met, however, with several exceptions to this rule.

CLINICAL HISTORY.-Emphysema, existing to an extent to compromise considerably the respiratory function, is characterized by habitually labored breathing, and inability to take active exercise without suffering from want of breath. The laborious breathing is manifested in both respiratory acts, but especially in expiration. The rhythm of the respiratory acts is altered; the inspiration is shortened, and the expiration prolonged. As chronic bronchitis generally coexists, cough and expectoration are habitually more or less prominent as symptoms. The cough is usually violent, paroxysmal, and characterized by a series of prolonged, spasmodic expiratory efforts, as in hooping-cough. The expectoration varies much in different cases as regards quantity and character. The acts of expectoration are difficult, and the sputa are frequently accompanied by an abundant, frothy, serous liquid, resembling soapsuds. Not unfrequently sputa streaked with blood are expectorated.

The affection is chronic, and unaccompanied by febrile movement. The pulse is feeble and the body cool. Owing to an accumulation of blood within the right cavities of the heart, the surface of the body presents venous congestion, and this, together with deficient oxygenation of the blood, may give rise to a cyanotic hue. In extreme cases lividity is marked. The paroxysms of coughing are accompanied with great congestion of the face and turgescence of the cervical veins. Symptomatic phenomena, aside from those referable to respiration and circulation, are accidental. The appetite and digestion may not be notably impaired; the body, for a considerable period, may be well nourished, but, after a time, slow, progressive emaciation takes place. The countenance has an expression of distress, which, conjoined with tumidity, and a dingy or livid hue, renders the physiognomy somewhat characteristic.

These symptoms accompany the affection when it exists to an extent to compromise considerably respiration. Existing in a moderate or slight degree, there is no habitual want of breath or labor of breathing. But the