tions of the mucous membranes that excite adenitis of the neighboring lymphatic glands seem to be especially subject to subsequent lymphatic tuberculosis.

The pathology of scrofula is that of tubercular foci, which are usually localized in certain groups of glands and show a tendency to spontaneous healing. In many cases suppuration of the infected glands occurs, especially with tubercular glands in the neck. In these instances the pus is usually sterile, and it is not known whether the suppuration is excited by the tubercle bacilli and their products or by a mixed infection of pus-organisms. An unhealed focus of tubercular adenitis may at any time discharge bacilli into the blood-vessels or the lymph-vessels; it is said that three-quarters of the cases of acute miliary tuberculosis originate in this way.

Symptoms.-I. General tuberculous lymphadenitis is a rare condition, and usually occurs in the negro race. The lymph-glands throughout the body are the seat of a diffuse tubercular infiltration. Acute cases resemble clinically Hodgkin's disease, but there is apt to be more fever.

2. Local Tuberculous Lymphadenitis.—(a) Cervical.—This form is frequently seen, especially in tenement-house and asylum children and in the negro race. The submaxillary glands are usually the first to be involved, and subsequently the cervical chains of glands become infected. The glands may remain isolated and mobile, but they tend to become fused so as to form large knobby tumors. Suppuration is common. For the details of this affection the reader is referred to works on surgery.

(b) Bronchial.—The bronchial glands are extremely subject to infection, and they may be involved with or without local lesions in the lung. Acute miliary tuberculosis is apt to result. (For details see Miliary Tuberculosis and Broncho-pneumonia.)

(c) Mesenteric (Tabes Mesenterica).-In this form the mesenteric and retroperitoneal glands are enlarged and tubercular. They may suppurate, or they may become encapsulated and infiltrated by lime-salts. Mesenteric tuberculosis may be primary or may complicate tubercular disease of the intestines.

The treatment of tubercular adenitis is that of tuber

culosis in general. Cervical tubercular glands may be

removed.

VIII. DISEASES OF THE NERVOUS SYSTEM.

1. DISEASES OF THE MEMBRANES OF THE BRAIN.

(a) DISEASES OF THE DURA MATER.

ACUTE EXTERNAL PACHYMENINGITIS.

Etiology.-Pachymeningitis is regularly secondary to injuries and diseases of the cranial bones and to suppurative disease of the middle ear and of the mastoid cells.

Pathology. The dura is thickened by a purulent infiltrate; the products of inflammation collect between the dura and the skull, forming a circumscribed abscess. The lesion is usually localized over one cortex. The inflammation may extend to the pia mater or to the venous sinuses.

The symptoms are usually obscure. Pain is usually referred to the seat of the lesion. Septic symptoms develop, and compression-symptoms may result in hemiplegia if the motor area be pressed upon.

The prognosis is good if the treatment be scientific and if the pia and the venous sinuses be not involved.

The treatment consists in trephining and draining the abscess-cavity.

ACUTE INTERNAL PACHYMENINGITIS.

Etiology.-Pachymeningitis interna is secondary to inflammation of the external surface of the dura, or complicates erysipelas, Bright's disease, pyæmia, pneumonia, puerperal fever, and the exanthemata.

Pathology. The inner surface of the dura is covered with fibrin and pus or with pus alone; the thickness of the dura is not usually involved. The inflammation is apt to extend to the pia and to the venous sinuses. The purulent exudation is usually circumscribed over the cortex.

The symptoms resemble those of a localized purulent meningitis. In the complicating cases the symptoms may be so obscured by those of the primary disease that the diagnosis is rendered obscure.

The prognosis is not good, owing to the liability to meningitis and thrombosis of the cerebral sinuses. The treatment is that of meningitis.

CHRONIC INTERNAL PACHYMENINGITIS. Etiology and Synonyms.-The disease is usually found in males over fifty years of age; it occurs in connection with insanity and degenerative diseases of the brain. Almost all the subjects are markedly alcoholic, and the disease is one almost exclusively of tramps and almshouse inmates. Synonyms: Hemorrhagic pachymeningitis; Hæmatoma of the dura mater.

Pathology. The disease is characterized by the growth of a new membrane upon the dura, usually involving a small area over one cortex. In the earlier stages this membrane resembles a brownish-red staining of the dura, and consists of large, thin-walled blood-vessels supported by a delicate connective-tissue framework. From these blood-vessels hemorrhages occur, constituting the principal feature of the disease. In the later stages the dura is thickened over the affected area by dense fibrillated connective tissue, and upon its inner surface the original membrane is found as already described. The dura may be from half an inch to an inch thick, and thus the brain becomes slowly compressed; the compression of the brain is further increased by hemor

rhage between the dura and the pia, which may occur at any time.

The symptoms are due to slow and to sudden braincompression.

Slow Compression.-Headache is prominent, constant, and usually localized. There are loss of memory and increasing stupidity. The gait is shambling, slow, and unsteady, but paralysis and ataxia are not observed. The speech becomes slow, faltering, and scanning. One or both pupils may be contracted. In the earlier stages of the disease these symptoms are not marked.

Sudden compression is caused by meningeal hemorrhages. The patient will become unconscious, with or without preceding convulsions, and will develop hemiplegia (see Meningeal Hemorrhage). The hemorrhage may occur spontaneously or after exertion, or after a blow or an injury to the head. In the latter instance the disease possesses great medico-legal interest. The hemorrhage may occur early in the disease and may be the initial symptom.

Prognosis. The disease is slow in its progress, extending over years. Rare cases of recovery have been reported. Death usually occurs from degeneration of the brain with. insanity, or from hemorrhage.

Treatment. As the diagnosis from syphilitic meningitis cannot in all cases be made, potassium iodide should be given in full doses. This treatment, however, is of no service in non-syphilitic pachymeningitis. The treatment of the disease is chiefly prophylactic. Quiet, easy employment, and the avoidance of severe bodily exertion should be enforced, to lessen the chance of meningeal hemorrhage.

SYPHILITIC PACHYMENINGITIS.

This disease will be considered under the heading of Syphilitic Disease of the Brain-membranes.