“Sad experience, and especially in recent times, has taught, that during the decomposition of organized matter, whether animal or vegetable, under the action of heat and moisture, certain exhalations take place, which possess properties in the highest degree injurious to the health of man. This is a truth which is attested by a multitude of medical authors. It is the good fortune of the inhabitants of Santiago, that the atmosphere in which they breathe does not so readily absorb, or act upon substances undergoing the process of putrefaction, as to engender those dreadful epidemics, which have carried off millions of lives, and are still reaping their harvest of mortality in various parts of Spain, North America, India, Mexico, Panama, Vera Cruz,[42] and many other regions of the Old and New World. “Were they not thus favoured by the natural salubrity of their atmosphere, the church-bells of the Chilean capital would be daily heard to toll the mournful knell of death, and every home would present the tearful scene of grief and lamentation. “But although in Santiago the action of the atmospheric air on substances in a state of putrefaction is not so active as to produce such epidemics as those alluded to, yet it cannot be denied that it is capable of acquiring such properties as make it exercise a most baneful influence on the public health: inducing attacks of dysentery, typhus and other fevers, which, from time to time, appear epidemically. In truth, to some general cause of this nature we must attribute those violent and fatal dysenteries which were so very prevalent in the year 1826, and which recurred in the months of March and April of the present year (1828). To a similar cause must be referred that vexatious sort of puerperal fever which in the year 1827 attacked such a number of women; and also those cases of typhus or _chabalongo_ which abound, with few exceptions, every year. “Reasoning on the generally received principle that air at a high temperature occasions a greater degree of exhalation from bodies than cool air does, and from what we know the influence of summer heat to be in other countries, we should suppose that diseases caused by miasmatous matter should be here more common in summer than in winter; but our acquaintance with this climate induces us to think differently on this subject.