employed, although care should be taken to prevent the children from swallowing any of the water or its being splashed into the Symptoms of tertiary hereditary syphilis should be treated in the same manner as similar symptoms in cases of acquired syphilis.

IV. LEPROSY.

Etiology.-Leprosy is at the present day principally a disease of the tropics. In the middle ages it was widely prevalent also in Europe, and only through rigid quarantine measures has it been possible to confine it to small areas of Norway, Sweden, Iceland, Russia, Roumania, Greece, Italy, etc. In recent years new foci of leprosy were found to have developed in Germany (in the vicinity

FIG. 80.-Bacilli shown in a section of the tongue from a case of tubercular leprosy; magnified 600 times. The bacilli are extracellular: B. bacilli in groups; Z, Z, zooglear masses, large rounded masses of bacili; (, bacilli in chains Leloir).

of Memel) and in the south of France; and, in any event, governments will do well to keep leprous patients under careful observation in order to prevent epidemie distribution of the pestilence.

Leprosy is without doubt an infectious disease, which has been successfully transmitted to criminals and also to healthy persons

in the act of vaccination. The exciting agent of leprosy is the leprosy-bacillus, which was first demonstrated by Hansen (1880) in leprous tissues. In their reactions to stains leprosy-bacilli resemble closely tubercle-bacilli, and they often lie together in cellsleprosy-cells in groups (Figs. 80 and 82). They are found, among other situations, in large number in scales of the skin, in the saliva, and in the nasal secretion. Possibly they gain entrance

into the body by inhalation, as leprosy of the nose is one of the earliest and most constant manifestations. The disease occurs between the twentieth and fortieth years of life, and children are almost always exempt.

Symptoms and Prognosis.-The period of incubation of leprosy may apparently be several years. Prodromes are frequently manifested in transient febrile movement, which is often attributed to malaria. Two varieties of leprosy have been distinguished, and they have been designated cutaneous leprosy and nervous leprosy; although, in the further course of the disease, the one variety generally passes over into the other.

In cases of cutaneous leprosy the earliest alterations appear in the skin. Here and there red spots develop, which in part disappear, but in part are replaced by brownish discoloration. In addition, thickening of the skin occurs, either in a diffuse manner or in nodular distribution-nodose, tuberous, or tuberculous leprosy. This thickening of the skin also may subside, but sometimes it persists. In consequence deformities occur, especially in the face. The chin, the lips, the nose, the eyelids, and the auricles become increased in size, and acquire a rigid, mask-like appearance. The face has been compared with that of a lion or a satyr, and the designations leprous leontiasis and satyriasis have therefore been employed. Some of the leprous infiltrates and nodules begin to break down, and leprous ulcers thus result upon the skin, which

FIG. 82.-Leprosy-bacilli from nasal secretion: fuchsin-methylene-blue stain; oil-immersion; magnified 1000 times (personal observation, Zurich clinic).

secrete small amounts of pus, present indolent granulations, and but slowly undergo cicatrization. The hair generally falls out, and the absence of the eyebrows and the eyelashes is especially noteworthy. The external lymphatic glands gradually and progressively become enlarged.

Diffuse leprous infiltrates and nodules develop not only upon the external skin, but also upon the mucous membranes, with especial carliness and constancy upon the nasal mucous membrane, but also upon that of the pharynx, the larynx, and the deeper air-passages. In consequence stenosis of the nares and the upper air-passages frequently results. The voice becomes hoarse and finally toneless. In addition, however, ulcers not rarely form, and frequently they perforate the cartilaginous septum of the On post-mortem examination the internal viscera also are

nose.

generally the seat of leprous infiltrates and nodules, although these often remain concealed during life. It is noteworthy that frequently the testicles are the seat of leprous new-formations, and they undergo progressive atrophy. Leprous new-formations have been observed also upon the conjunctiva, the cornea, and the iris. Nervous leprosy generally begins with circumscribed or diffuse thickening of the peripheral nerve-trunks, earliest and most constantly in the ulnar nerve, just above the internal condyle of the humerus, and in the great auricular nerve. Circumscribed areas of the skin then present hyperesthesia. Gradually this is replaced by cutaneous anesthesia, which frequently is at first partial and involves especially painful and thermic sensibility-anesthetic leprosy. Gradually trophic and vasomotor disturbances are superadded. Vesicular elevations appear upon the skin-leprous pemphigus-in the fluid of which leprosy-bacilli can be demonstrated. Occasionally perforating ulcer of the foot develops. It may also happen that the phalanges of the fingers and the toes are exfoliated after painless ulceration-so-called mutilating leprosy. The skin often acquires a brownish or a bright-white appearance in places -macular leprosy. Occasionally edema of the hands and the feet develops, the overlying skin being deeply cyanotic, whence the name blue edema. Such muscular paralysis as is present exhibits peripheral characteristics. The paralyzed muscles exhibit also increased mechanical irritability and degenerative electric reaction. Paralysis is often complicated by muscular contractures and atrophy.

The course of leprosy is chronic, and often extends over many years. Death occurs, in the presence of progressive exhaustion or of leprous ulcers, as a result either of septicemia or of intercurrent disease, as, for instance, pneumonia. Although leprous newformations may in part undergo involution, permanent recovery, however, is extremely rare, so that the prognosis is unfavorable.

Diagnosis.—A positive diagnosis of leprosy is possible only by bacteriologie methods. Leprosy-bacilli can be demonstrated in the nasal mucus, the sputum, the urine, and the blood of leprous patients. The contents of cantharidal blisters also have usually been examined for leprosy-bacilli with success. In a patient under my care innumerable leprosy-bacilli were found in the scales from the skin. From the clinical manifestations alone leprosy might readily be confounded with tuberculosis. Nervous leprosy is not rarely attended with symptoms of syringomyelia and Morvan's disease (Vol. I., pp. 566 and 567).

Anatomic Alterations.-Diffuse infiltrates and circumscribed nodular accumulations of round cells developing in all of the viscera are distinctive of leprosy. Within these leprosybacilli are encountered, generally enclosed in cells, some of which have developed into polynuclear giant-cells, and are filled with

vacuoles. In cases of nervous leprosy, peripheral nerve-trunks are the seat of leprous formations, with resulting degenerative destruction and loss of nerve-fibers. Leprosy-bacilli have been found also in the brain and the spinal cord.

Treatment. In order to prevent the spread of leprosy by inoculation the most reliable prophylactic measure is rigid segregation of the patients in special hospitals (leproseries). In addition the sputum, the urine, the nasal secretion, and the cutaneous scales of the patient should be thoroughly disinfected. Leprosy-bacilli have been found also in the sweat.

No specific remedy for the treatment of leprosy is as yet known. Recently, curative serum has been employed, although the experiences thus far reported from its use are by no means encouraging. Among internal remedies successful results have been reported especially from the use of salicylic acid and sodium salicylate. Inunctions with salicylated ointment, or with ichthyol, and sulphurous baths also have been warmly praised. Chaulmoogra oil (in doses up to 15.0-fluidounce-daily) has been employed in Japan with success. Attention should be especially directed to sustaining the strength of the patient by means of good food, and by keeping in the open air a good deal, and to preventing septic infection through ulcers.

V. ZOONOSES.

All those infectious diseases are designated zoonoses that are usually acquired by human beings through inoculation from animals.

ANTHRAX.

Etiology.-Anthrax results from inoculation with anthraxbacilli, which were first described by Rayer in 1851, and were subsequently carefully studied especially by Koch. The organisms are rods from 5 to 20 long (Fig. 83), staining readily with aniline dyes, susceptible of artificial culture and of successful inoculation upon animals. Among domestic animals anthrax occurs most frequently in cows; less commonly in horses, sheep, and swine. Other animals also, particularly herbivora, as, for instance, the stag, the deer, are, however, readily amenable to infection. In man, anthrax is most frequently acquired by inoculation, which occurs with especial readiness in persons that come into contact with animals suffering from anthrax, such as hostlers, veterinarians, shepherds, butchers, etc. Should blood or discharges from animals suffering from anthrax gain entrance into wounds in