Typhoid fever is, one might almost say, alarmingly prevalent among young soldiers and civilians in the East. It is very common among them during the first two or three years after their arrival. Fortunately, the liability decreases with length of residence. Apparently a sort of acclimatization, or rather habituation, to the poison is established with time, just as tends to be the case with other organic poisons. It is not unlikely that the relative exemption if—such there be—of the native races is owing to a like immunizing effect produced by, living in constant contact with typhoid and similar toxic agents, or to an attack in childhood. On visiting native cities—Chinese cities, for example—one is filled with amazement at the state of filth in which the people live, and not only live but thrive. The streets are narrow and never cleansed; the common sewer lies beneath the flagstones, and through the interstices between the stones can be seen the black, stinking slush in the sewer. The sewage is not confined in a well-laid cemented drain, but soaks through the loosely laid, uncemented stones, and thoroughly saturates the ground on which the tumble-down, overcrowded houses are built. Night soil is allowed to remain in wooden buckets inside the houses awaiting collection by the soil merchant, who sells it to the market gardener and the farmer. Urine is accumulated in earthenware jars, and is similarly disposed of. The houses are rarely swept and cleaned, hardly ever repaired. In every corner are filth and rubbish. And yet in such circumstances the population seems to thrive. Doubtless, where the European would almost surely contract typhoid and other filth diseases, the natives have obtained a high degree of immunity.
In Eastern countries little or no care is taken to prevent contamination of the wells and streams with sewage matter, and unless foreigners are very careful about boiling their drinking-water and the water in which their plates, etc., are washed, avoiding salads and all uncooked vegetable dishes, refraining from bazaar-made drinks, and protecting their food and food-dishes from flies and other mechanical trans-
