AIR. Few persons are sufficiently aware, that an unwholesome air is the common cause of disease. They generally pay some attention to what they eat and drink, but seldom regard what goes into the lungs, though the latter often proves more fatal than the former. Air vitiated by the different processes of respiration, combustion, and putrefaction, or which is suffered to stagnate, is highly injurious to health, and productive of contagious disorders. Whatever greatly alters its degree of heat or cold, also renders it unwholesome. If too hot, it produces bilious and inflammatory affections: if too cold, it obstructs perspiration, and occasions rheumatism, coughs, and colds, and other diseases of the throat and breast. A damp air disposes the body to agues, intermitting fevers, and dropsies, and should be studiously avoided. Some careful housewives, for the sake of bright and polished stoves, frequently expose the health of the family in an improper manner; but fires should always be made, if in the height of summer, when the weather is wet or cold, to render the air wholesome; and let the fire-irons take care of themselves. No house can be wholesome, unless the air has a free passage through it: dwellings ought therefore to be daily ventilated, by opening the windows and admitting a current of fresh air into every room. Instead of making up beds as soon as people rise out of them, a practice much too common, they ought to be turned down, and exposed to dry fresh air from the open windows. This would expel any noxious vapours, and promote the health of the family. Houses surrounded with high walls, trees, or plantations, are rendered unwholesome. Wood, not only obstructs the free current of air, but sends forth exhalations, which render it damp and unhealthy. Houses situated on low ground, or near lakes and ponds of stagnant water, are the same: the air is charged with putrid exhalations, which produce the most malignant effects. Persons obliged to occupy such situations should live well, and pay the strictest regard to cleanliness. The effluvia arising from church-yards and other burying grounds is very infectious; and parish churches, in which many corpses are interred, become tainted with an atmosphere so corrupt, especially in the spring, when the ground begins to grow warm, that it is one of the principal sources of putrid fevers, which so often prevail at that season of the year. Such places ought to be kept perfectly clean, and frequently ventilated, by opening opposite doors and windows; and no human dwelling should be allowed in the immediate vicinity of a burying ground.--The air of large towns and cities is greatly contaminated, by being repeatedly respired; by the vapours arising from dirty streets, the smoke of chimneys, and the innumerable putrid substances occasioned by the crowd of inhabitants. Persons of a delicate habit should avoid cities as they would the plague; or if this be impracticable, they should go abroad as much as