On looking into a mirror there will be seen, on either side of the throat, two arches, formed by folds of mucous membrane; these are known as the pillars of the throat. Between these pillars, on either side, is an almond-shaped body called the tonsil. In health the tonsil should not protrude beyond the anterior pillar. _Causes of Diseases of the Nose and Throat._—Exposure to wet and cold, when insufficiently clad, or, even worse, sitting still with damp skirts or shoes on. A still more potent factor than exposure to cold is the relative degree of humidity of the atmosphere; great humidity is frequently accompanied by epidemics of influenza. Exposure to very high winds; sudden changes of temperature; the very dry air and the overheating of houses; insufficient covering at night; the inhalation of irritating vapors and finely divided mechanical irritants. Also, gastro-intestinal affections and uric acid. Chronic enlargement of the tonsils predisposes to tonsillitis and to all the infective and contagious throat diseases. In addition, the breath is apt to be fetid, and swallowing the mucus, germs, and toxins has a deleterious effect on the stomach and general health. Mouth-breathing and anemia often follow, and there is an increased liability to inflammation of the eyes. _The Importance of a Healthy Condition of the Throat and Nose._—The nose and throat are the portals of entrance to the bronchial tubes and lungs, and it depends on the condition of their mucous membranes whether the germs of disease will find lodgment here and be carried down into the bronchial tubes and lungs, or whether they will be expelled with the mucus. Any irritant which destroys the vitality of the epithelium covering the mucosa, or a local congestion which interferes with the nutrition, circulation, and secretions of the part, offers favorable conditions for the culture of bacteria normally present. Also, anything which will cause a lowering of the general health, and thereby lessen tissue resistance, acts as a predisposing cause to local inflammation, while the germs themselves excite inflammation by their active growth _in loco_. From these facts will also be seen the importance of having cut short, as rapidly as possible, any congestion or inflammatory troubles of the nose and throat. _Prevention of Nasal Catarrh and Sore Throat._—First in importance comes attention to the general health. Under this must be considered the clothing, food, ventilation, and exercise. The clothing should be light, yet sufficiently warm to be a protection against the cold and winds. Heavy shoes with thick soles are necessary to protect the feet, and it is not so much the matter of getting wet as it is of sitting down with damp clothing on. An atmosphere filled with dust in sweeping should not be tolerated in any well-kept house.