of the blood (serum) has to be eliminated internally through the mucous membranes. Cooling, i. e., the sudden action of comparatively low temperature on the warm surface of the skin—for instance, when one sits in a draught of air—may check transpiration, and so cause the fluids to tend inward in such volume as to overtax the capacity of the mucous membrane of the lungs or the intestines, more rarely of the kidneys, the result being catarrh. But catarrh and coughing are two different things: as for "dry cough," it can never arise from cold. That it results from the inhalation of impure, vitiated air, the reader knows already. It is true that obstruction of the breathing apparatus, as "rattling" in infants, and hawking and hoarseness in grown persons, results from retention of serum; but that this obstruction is not connected with taking cold must be admitted, at least in all cases where the patient has not quit his chamber, or even his bed. As a matter of fact, no one takes a cough from a cold wall or from an open door. The conclusion to be drawn from all this is, that the coughs, hoarseness, and sore-throats, from which those persons suffer in winter who are ever on their guard against colds, are produced, not at all from cold, but from its contrary, overheating of the skin, whose evaporation is feebler the nearer the external temperature approaches that of the body. In this case there is a suppression of the action of the skin, but it is produced not by cold but by improper warming—or, as it is more properly called, by pampering. A hot bath, a cold pack, or a good, lively walk, will work wonders in "loosening" a hard cough. At first, it is true, the patient will cough harder than ever; but this effect is not due to the "cold wind," but to the fact that the accumulated mucus, once started, is expelled en masse. The oftener the patient resorts to the bath, to the pack, and to walking, the less frequent are the fits of coughing, and the freer and easier does he breathe.
b. Reduction of Temperature.—The body's temperature is normal when in the armpit it is about 95° Fahr. Food and drink are stimulants, and the skin is the radiating surface which gives off the surplus heat. If this elimination is not sufficiently active, the body becomes overheated, and this manifests itself by shivering. Overheating is the result when one eats and drinks much, at the same time parting with but little heat. The chill so produced is usually called "inward cold," but this is an error: it is overheating. That this is so is shown from the fact that when on the morning after a "social evening," during which we were overheated, we feel chilly, we have only to take a walk until perspiration is set up; we then feel warm again in spite of a considerable cooling off. And this, by-the-way, is the very best cure for the "Katzenjammer." We live in a climate where it is far easier to heat the body than to cool it. Hence one of my counsels against catching cold is, that the weakly, coughing reader of sedentary habits should not overheat himself with strengthening food, so