Local temperature, that is, the heat in the several regions of the body is determined by conditions which control the circulation of the blood, and the function of nutrition or food appropriation. If the circulation is free in a part, its temperature is maintained; if, from any cause, the flow of blood is retarded, the local heat will be reduced. Any one may put this to the test by encasing the hands in somewhat tight gloves when the weather is cold. The pressure prevents the free passage of the blood through the vessels, and the temperature falls. There is no warmth of any kind in the gloves; they act simply as non-conductors of heat, and prevent the heat generated within the body from passing off. For example—if a piece of lint or rag be dipped in cold water and laid on the skin, and a sheet of impervious or non-conducting material, such as india-rubber or thick flannel, is wrapped closely round, the heat of the body will raise the cold water to a temperature at which it will be given off as steam the moment the covering is removed. When the extremities are enclosed in thick or dense coverings, their temperature will depend on the amount of heat generated within them, and if the flow of blood through the vessels is arrested or retarded, nothing is gained, but everything lost, by the measures taken to protect them from the external cold. This is a matter of the highest practical moment, and needs to be thoroughly understood. The feet can not be kept warm unless the blood circulates freely in the extremities, and that will not be the case if the boot, shoes, or stockings are tight. These last-named articles of clothing are practically the worst offenders. A stocking encircling the foot and leg closely and enveloping every part, with special pressure at the instep, around the ankle, and above or below the knees, must inevitably tend to oppose the circulation and so reduce the natural heat. The arteries which bring the blood to the extremity are set deeper than the veins that carry it back, and, as the latter are provided with valves which open toward the heart, it is too commonly supposed that the “support” afforded by the stocking will favor the return of blood more than it can impede the deeper supply-currents, and so help the circulation; but practically we know this is not the fact, for a tight stocking ensures a cold foot, and the chilliness of which many persons complain is mainly caused by the practice of gartering, and wearing stockings which constrict somewhere or everywhere.