Heat, Internal.--There is a usual (normal) temperature in all the blood and tissues of the body. If the body be either warmer or colder than this point (98.4 deg. Fahr.), its health is interfered with. A "clinical thermometer" is used to ascertain whether the bodily temperature is normal or not. It is to be had at every druggist's, and is of great importance in a household. By its means the rise of temperature can be detected often before any serious symptoms set in, and due means taken to check trouble in its early stages. The instrument is used by putting it under the armpit, or, with children, between the legs, so that the mercury bulb is entirely enfolded and hidden between the arm, or leg, and the body. Left in this position for five minutes, it is taken out and read. It may also be held in the mouth, under the tongue, with lips close on it. Where a good deal of fever is shown, as by a rising of the mercury to 101 deg., measures to reduce it should at once be taken, as shown in the articles on various kinds of Fever. By watching the temperature, and taking it from time to time, we can see when cooling is sufficient. Where the temperature is too low--that is, below 98-2/5 deg.--rub all over with warm olive oil, and clothe in good soft flannel. Other methods for increasing vital action may also be tried, as given in many of our articles. Heel, Sprained.--Often in sprains all attention is given to the bruised and torn _muscles_, while similarly bruised and torn _nerves_ are overlooked; yet upon the nerves the perfect healing of the muscles depends. Hence, in a sprain of the heel we must be careful not to direct attention to the heel exclusively. That may be bathed (_see_ Bathing Feet) and duly rubbed with oil. A good plan is to apply cloths dipped in cold water and vinegar. Keep the limb perfectly still, and do not attempt to use it for at least a fortnight. After this it may be cured to all appearance, yet a weakness may be left which prevents anything like the full and free use of the limb. It may be all right when resting, but suffers when used for any length of time: this indicates pretty plainly that _rest_ is needed, and is an essential thing for cure. But besides this rest, the foot should be packed during the night in soap lather (_see_ Lather and Soap). Wash the foot in vinegar or weak acetic acid, rub the whole limb from the ankle _upwards_ in such a way as to draw the blood up from the foot, avoiding all down-strokes. Use a little olive oil in this rubbing. Note that the whole limb needs treatment. The juice of _Lady Wrack_, such as is to be found on the west coast of Scotland, is an excellent remedy for sprained joints; but we only mention it, as it must be inaccessible to many of our readers.