The dire struggle of the Indian Mutiny led to the first attempts to clothe and treat the soldier in a somewhat more rational fashion, and since then great improvements have been effected; but a great deal more remains to be done, especially in the matter of utilising our recently gained knowledge of the causation of malaria, before our military statistics can be expected to show how little this evil reputation is due to the climate itself, and how much has really been caused by human misdirection. No amount of sanitary improvement can be expected to render Bombay a comfortable place of residence in the dog days, and apart from localities at considerable elevations, where the climate is really temperate, it is hopeless to expect that anything in the way of actual colonisation can succeed in the climates with which we are dealing; but with due care and attention to sanitary laws, as modified by the altered conditions, there is no reason why the rates of sickness and mortality should be much more formidable than elsewhere. In the following pages the writer has endeavoured to put into popular form the principal points of personal hygiene as applied to hot countries, and as they are intended mainly for the non-professional reader, all technical terms have been, as far as possible, avoided, and words in popular use, such as germs, &c., have been substituted for the more exact nomenclature of science. Should any of his medical colleagues care to read a merely popular work, they can easily supply for themselves, in place of these vague, popular words, the more precise terminology in use amongst ourselves. The climates of the hotter parts of the world vary even more widely than those of the temperate zone, so that it is often impossible to offer suggestions applicable to all of them; and on this account it is extremely important that the intending resident or visitor to them should be able to ascertain what is the exact nature of the climatic conditions with which he will have to cope, so that it is absolutely essential to include within the scope of a work like the present some account of the climates of the various countries included in the enormous area under consideration. On this account the little book has been divided into two distinct parts, the first of which is devoted to personal tropical hygiene, while the second, which deals with climate, is necessarily mainly a dry mass of tabulated information, of which only the few pages devoted to the country he proposes to visit is likely to interest the individual reader.