Based on the foregoing and other data, we shall now submit certain general conclusions on the climate of Brazil, and its influence on the human constitution in health and disease; these conclusions must be taken as more especially referring to the seaboard and the large cities on the coast; and the reader should bear in mind that some allowance must also be made for the difference in position and latitude of the northern, the southern, and the central provinces. We would further premise, that these observations are founded on our own personal experience of nearly a quarter of a century, and prior to the advent of the yellow fever which, for the last four or five years, has infested the maritime cities of the empire, and on which we shall presently offer some remarks.
The great characteristic of Brazil, as compared with other countries, is the general equability of its climate, and which constitutes, in fact, the chief element of its salubrity. This unparalleled uniformity of temperature must be chiefly ascribed to the absence of high and mountainous regions, and of all arid and sandy deserts, aided by the genial influence of refreshing showers at all seasons of the year; it is further maintained by the perpetual verdure of the country, and by a cool, powerful, and never-failing monsoon, laden with moisture, and sweeping along the entire line of coast direct from the Southern Atlantic. Thus, even in the height of summer, the diurnal heat is rarely found oppressive to the European, and the nights are almost invariably serene and beautiful, and unattended with much deposition of dew, especially in the northern and central provinces; so that the delightful coolness of tropical moonlight may be enjoyed undisturbed by those visions of fever and malaria which float before the imagination in less favoured lands. If precautions be observed to avoid exposure to direct currents of air, the windows of the sleeping chamber may also be left open with impunity at all seasons of the year; an advantage that can scarcely be over estimated in high latitudes, as disposing to sound and refreshing sleep; which, more perhaps than any other influence enables the European constitution to resist the deleterious effects of climate, just as a succession of hot and sleepless nights invariably predisposes the human system to be impressed by every tropical malady.