The nosology of Zanzibar is remarkable for the prevalence of urinary and genital diseases; these have been roughly estimated at 75 per cent. Syphilis spreads wide, and where promiscuous intercourse is permitted to the slaves it presents formidable symptoms. The ‘black lion,’ as it is popularly called—in Arabic El Tayr or El Faranj; in Kisawahili, Bubeh, Kiswendi, or T’hego—will destroy the part affected in three weeks: secondaries are to be feared; noses disappear, the hair falls off, and rheumatism and spreading ulcers result. Gonorrhœa is so common that it is hardly considered a disease. Few strangers live long here without suffering from irritation of the bladder, the result, it is said, of hard lime-water: and the common effect of a cold or of stricture is severe vesical catarrh. Sarcocele and hydrocele, especially of the left testis, according to the Arabs, attack all classes, and are attributed to the relaxing climate, to unrestrained sexual indulgence, and sometimes to external injury. These diseases do not always induce impotence or impede procreation. The tunica vaginalis is believed to fill three times: as in elephantiasis the member is but a mass of flesh, a small meatus only remaining. The deposition of serum is enormous; I have heard of six quarts being drawn off. The natives punctuate with a heated copper needle, and sometimes thus induce tetanus: Europeans add injections of red wine and iodine. The latter is also applied with benefit in the early stage to sarcocele; and both complaints have yielded, it is said, to the galvanic current. Strangers are advised at all times to wear suspensory bandages. Elephantiasis of the legs and arms, and especially of the scrotum, afflicts, it is calculated, 20 per cent. of the inhabitants: Arabs and Hindus, Indian Moslems and Africans, however dissimilar in their habits and diet, all suffer alike. It is remarked that the malady has never attacked a pure white, European or American: perhaps the short residence of the small number accounts for the apparent immunity. Similarly, in the Brazil I have never seen a European stranger subject to the leprosy, or to the goître, so prevalent in the great provinces of São Paulo and Minas Geraes. The Banyans declare that a journey home removes the incipient disease, or at least retards its progress: it recurs, however, on return to Zanzibar. The scrotum will often reach the knees; I heard of one case measuring in circumference 41 inches, more than the patient’s body, whilst its length (33 inches) touched the ground. There is no cure, and the cause is unknown. The people attribute it to the water, and possibly it may spring from the same source which produces goître and bronchocele.