The leading diseases are consumption, a common disease in hot, wet countries; diarrhoea, dysentery, cholera infantum, and fevers, worst of which is the yellow fever, which is present in Havana every month of the year, although much worse at certain times than at others. It is said that portions of Havana are permanently infected by yellow-fever germs, but Surgeon-General Sternberg, Dr. Wyman, Supervising Surgeon-General of the Marine Hospital Service, and other authorities say that by proper sanitary regulations and careful quarantining, the city may be made free of the disease and kept so, as is the case in Jamaica, where the English have had control for years. The work of sanitation will be difficult and expensive, and years will be required to accomplish it, but it must be done before Havana's future is assured. Sewers are few and far between, and those which exist are filled with refuse from the streets and are never cleaned, as the odours that rise from them constantly most disagreeably testify. They empty into the bay. Most of the drainage is surface, and as the city lies so low that a heavy wind across the waters of the bay will inundate many of the streets, it will be understood that the drainage is sluggish, and that what should be carried off by water is usually left to be rotted and dried by the sun--except in the rainy season, when it rots without drying. Much of the lower part of the city is built on swamp and "made-land," and what this means for the health of those who live upon it needs no elucidation. The following statement, made by José M. Yzquierdo, civil engineer, of Havana, under date of September 28, 1898, will throw some light upon street-sweeping contracts in Havana, show why the work cannot be properly done, and also indicate the part that the city authorities have always taken in the good cause: