peritonitis, and chronic inflammation of the tracheobronchial glands.

Pathology. A fibrinous exudate, later the development of fibrous tissue in the shape of dense bands surrounding the blood-vessels, trachea, and bronchi, often forms. The tissues undergo consolidation from contraction of the fibrous bands, producing pressure effects upon the veins, the aorta, the nerves, and may frequently be great enough to constrict the trachea and some of the larger bronchi.

Symptoms. The symptoms of this disease are often obscured and masked owing to the primary condition which precedes the disease, such as the inflammation of the pericardium, pleura, bronchi, and lung tissue. The disease may be diagnosticated from an increased fullness in the jugular veins, which steadily increases. This will be especially noted during inspiration, and lessened in expiration, the pulsus paradoxus being associated with the condition. Pain is present behind the sternum, which may radiate to the shoulders, back, neck, or chest. Dyspnea, increased upon slight exertion, is common. The pulse is rapid, small, easily compressed, and of low tension, besides having the character of the pulsus paradoxus. Cough with expectoration, followed later by cyanosis, is a common symptom. If constriction of the inferior vena cava occurs there will be swelling of the liver, ascites, and dropsy of the lower extremities. Fever may or may not be present.

Physical Signs.-As a rule, there is an increase in the area of precordial dullness; the apex-beat of the heart is absent, the sounds being faint though regular.

Diagnosis. This is extremely difficult, and must often be made by exclusion.

Prognosis. The prognosis is unfavorable.

Treatment. The treatment is palliative, symptomatic, and supporting.

ABSCESS OF THE MEDIASTINUM.

Etiology. All the causes which have been mentioned. under inflammation of the mediastinum may give rise to abscess, provided some pyogenic micro-organism be present. The streptococcus infection produces a severe spreading variety, the staphylococcus infection, as a rule, giving rise to the milder, more circumscribed forms. Trauma is Trauma is a frequent cause. The

condition may result from actinomycosis, from erysipelas, pyemia, variola, scarlet fever, measles, enteric and typhus fever, and from other infectious diseases. The disease occurs more frequently in males than in females.

Pathology.-The seat of abscess is most frequently in the anterior mediastinum. The pathology is that of abscess; the pus finds its way between various organs, and some of these may be perforated. If the infection be of a slow or chronic nature the abscess wall may be quite thick. Various forms of micro-organisms have been isolated from the pus.

Symptoms. If the abscess be acute, the ordinary signs of purulent inflammation are present, such as chill, fever, sweating, anorexia, coated tongue, vomiting, constipation which is followed by diarrhea, loss of flesh, anemia, great depression, and muscular weakness. Dry spasmodic cough, later accompanied by expectoration, which is often purulent and bloodstained, is a symptom. The local manifestations are indefinite in character; there may be a sense of fullness and constriction behind the sternum, which may give place to a constant dull, aching pain. Tenderness upon pressure is present over the sternum. If pressure upon the veins take place, signs of venous engorgement are noticed, and in pressure over the vena cava ascites and edema of the lower extremities result. Pressure upon the great veins gives rise to murmurs, and pressure upon the esophagus results in dysphagia. If there is pressure upon the laryngeal nerves, paralysis of the vocal cords is noted. The physical signs vary, depending upon the location of the abscess. The heart may be displaced; the sounds are apt to be obscured but regular. The pulsus paradoxus is likely to

be present.

Prognosis. If the abscess can be evacuated the prognosis is more favorable than in the deep-seated cases.

circumstance it is a very serious affection.

Treatment. The treatment is surgical.

Under any

TUMORS OF THE MEDIASTINUM.

BENIGN TUMORS.

Lipomata, fibromata, enchondromata and osteomata rarely occur in the mediastinum. Dermoid and echinococcus cysts have been encountered in this locality.

MALIGNANT TUMORS.

Carcinoma of the Mediastinum.-This tumor occurs more commonly as a primary growth than as a secondary, being most common in the anterior mediastinum. They occur most frequently between the ages of fifty and sixty.

Sarcoma of the Mediastinum.-The most common seat of this tumor is also in the anterior mediastinum, it being more frequently primary than secondary.

Secondary carcinoma also occurs in the mediastinum.

Symptoms. Tumors of fairly large size soon produce symptoms of pressure upon the heart or its vessels, the lung, the recurrent laryngeal nerve, the trachea, the bronchus, the large blood-vessels, such as the superior or inferior vena cava, the esophagus, and the sympathetic nerves. The symptoms are those of dyspnea, cough, frequently of an aneurysmal character, difficulty in swallowing, variation in the size of the vessels, and other circulatory disturbances. Cyanosis and enlargement of the thoracic veins arise due to the attempt at collateral circulation.

The physical signs are varied. If the tumor be very large, upon inspection there may be bulging of the sternum and ribs, and these bones may become eroded. If the growth push the heart forward, marked pulsation may be noted. Upon inspection, slight cyanosis and edema of the superficial veins may also be apparent. Upon palpation the vocal fremitus is found to be greatly decreased or absent. Upon percussion, dullness merging into flatness is present over the affected area. Upon auscultation indistinct or absent breath-sounds, with decreased or absent vocal resonance, is noted. If the tumor be situated anteriorly to the heart, the apex-beat will be faintly visible or absent, and the heart-sounds. upon auscultation will be distant and muffled. If the tumor be carcinomatous in nature, enlargement of the axillary and cervical lymphatic glands will be noted if these have become invaded by the spread of the growth.

Prognosis. The prognosis is grave.

PART IV.

DISEASES OF THE DIGESTIVE TRACT.

DISEASES OF THE MOUTH.

CATARRHAL STOMATITIS.

Definition.-An inflammation of the mucous membrane of the mouth.

Synonyms.-Acute stomatitis; simple stomatitis.

Etiology. The disease is most frequent in children, but may also occur in adults. The inflammation appears in the form of erythematous patches, so that the surface is drier than normal; or a catarrhal inflammation develops, with some thickening and increased secretion.

Improper food, either too hot or pungent, prolonged sucking of an ill-developed nipple, or unclean feeding bottles are causes. Dentition may be a cause; and in adults, tobacco, stimulating food, alcohol, or an irritation from a carious tooth.

Some drugs, such as mercury, arsenic, lead, iodin or bromin, may cause the disease. It may be the result of gastrointestinal disturbance, and occurs in some of the specific fevers, such as scarlet fever and measles, rarely in tuberculosis, carcinoma, and diabetes.

Symptoms. The symptoms are pain, heat, discomfort, dryness of the mouth, and difficulty in swallowing. The child is fretful, saliva drivels at the mouth, and the patient may become wasted and feeble. There is usually slight fever, accompanied by vomiting and diarrhea.

Treatment. The treatment consists in cleanliness, careful feeding, and the use of mild alkaline mouth-washes. If pain be great, ice may be used, or a weak solution of cocain painted upon the erythematous patches. A mild purge is often advantageous.

ULCERATIVE STOMATITIS.

Synonym.-Putrid sore mouth.

Etiology. The disease most frequently occurs in children between the ages of four and sixteen, and is usually due to bad sanitary surroundings, or a local irritation such as a decayed or carious tooth. Improper feeding may give rise to the affection.

Pathology. The pathology consists in a localized necrosis of the buccal mucous membrane with surrounding inflammatory infiltration. The ulceration spreads superficially.

Symptoms. The disease commonly appears first at the margin of the gum in the region of a molar tooth, oftener on the left than on the right side. The gum is red and swollen, and bleeds easily. The mucous membrane soon ulcerates, leaving a dirty yellow or grayish ulcer. The cheek and tongue upon the implicated side are also affected, and the ulceration may spread to the lips.

The breath is offensive, and the lymphatic glands of the neck are enlarged. The tongue is thickly coated. The duration of the disease depends upon the extent of severity of the affection.

Treatment.-Alkaline washes for the mouth, or peroxid of hydrogen in small doses, are effective. Chlorate of potash, locally, has been recommended by some authorities.

APHTHOUS STOMATITIS.

Synonyms.-Aphthæ; vesicular stomatitis.

Etiology. The affection occurs most frequently in children, and the usual causes which have been indicated in other forms of stomatitis are also prominent here. The disease occurs occasionally in adults, in whom it is most likely due to some local irritation.

Symptoms. Small papules, either single or in groups, occur in parts of the mouth, most commonly upon the inner surface of the lower lip. At the end of twenty-four hours the epithelial covering is lost, and a small oval, whitish patch, with raised edges, makes its appearance. This disappears in a day or two and leaves a small conical ulcer behind. Pus formation does not take place. The sore heals in a few days,