Notes on Certain Tropical Diseases.

The subject of tropical mortality has in the past received a moderate share of attention, and actuaries have at their command various mortality experiences for climates other than temperate. These without exception show higher, in some cases much higher, mortality than that to be expected in this country. These notes have been made with the object of giving some short account of various tropical diseases to which this higher mortality is no doubt to be attributed. The very marked improvement during recent years in tropical vitality among assured lives can be dated from the closing years of last century, when the true cause of such diseases as malaria, filaria, and yellow fever was discovered to be their propagation by certain mosquitoes. Correct methods of prevention or at any rate mitigation of the spread of these diseases were then able to be taken. Although mosquito-borne fevers account for most of the increased mortality in the tropics, certain diseases of the intestinal tract, such as cholera, dysentery and sprue, have their part in bringing about this undesirable state of affairs. Other diseases which cannot be held to have much effect on assured lives , however disastrous they may prove to the native populations, are leprosy, hook-worm disease, beriberi, and pellagra ; and of these some shorter notes are given.