The great changes which have lately taken place in India—the progress of railways, the extension of commerce, and the impetus which is likely to be given to the emigration of Europeans to those vast fields of enterprise—cannot but add peculiar interest to any inquiries tending to throw light on the causes which affect the health or life of Europeans in that country. The difficulties of arriving at any sound conclusions on these subjects have always been great. In dominions so widely spread, comprising all climates, from the most delightful temperatures of perpetual spring to the fever-haunted jungles and deadly swamp, every cause that affects the health of man may be found at work.