Few of the primary causes of pestilence among large bodies of men are so powerful or so extended in the range of their action, as extreme and long continued cold, want of sufficient clothing and shelter, and depression of the mind. Coincident with many of the epidemics which are wont to prevail in this country, these circumstances are almost, without exception, found to be present; and if they are not admitted to be considered as the sole and exclusive causes of the prevalent disease, it is proved that they are co-agents or adjuvants of the very first importance. Much of the continued fever which infests the poorer classes of our countrymen, and almost all the pleurisies, colds, and consequent consumptions, which prevail more or less among the various ranks every winter, are in a very great degree dependent on the extreme cold of the season which suddenly sets in, and against which the dress of the inhabitants of these islands is insufficient to provide. The labouring classes suffer much, more particularly from the action of cold and the inclemency of the weather. They are generally very scantily clothed, nay, they are sometimes scarcely covered, and the consequence is, that the cold makes a strong and lasting impression, the circulation on the surface is suddenly impeded, the perspiration is checked, and the whole fabric involuntarily shivers. Now these are the very first symptoms of fever, and unless the constitution is possessed of stamina to remove those symptoms without loss of time, and to establish the circulation in its vigour again upon the surface of the body, that disease, or some other, will undoubtedly be established. When a body thus affected with cold is placed in a warm situation, there supervenes an excitement or reaction, which is marked by increased force of the circulation, and with redness and heat of the skin, a condition which is often experienced by persons who go immediately to the fire when newly arrived from a journey in the cold. When that reaction ceases, and is followed by a sense of coldness and by shivering, which again is succeeded by reaction, fever, in its proper sense, is established, and will assume a character of violence, lowness, or malignity, according to circumstances. The clothes, the house, and the diet of the working man, are insufficient to protect him against the action of the cold, and to resist its operation when once it has fastened upon him; and thus it is, that to comparative want and to many privations, there is so often conjoined so much disease.