Our knowledge of the specific cause of scarlet fever is not as complete as that of diphtheria, but we have much useful information which is of importance from a hygienic standpoint. As in diphtheria, the specific poison is probably produced in the throat of the patient, and may therefore be spread by the dried secretion from the mouth and throat. The most common means of contagion, however, is the skin, which peels off in the later stage of the disease, infection being produced by the inhalation into the nostrils of some of the diseased particles. A predisposing factor which applies alike to diphtheria and all other throat affections is the abnormal condition of the nose and throat. When these important parts are in an unhealthy condition, where mouth breathing exists and other conditions inimical to normal health, the patient is more predisposed to all forms of maladies of this region, and the attack when developed is more apt to be of a serious character. The more ordinary forms of sore throat, such as tonsilitis, are frequently due to defects in the sanitary conditions and surroundings of the home. While modern sanitary plumbing, when properly constructed, adds much to the convenience of the household, it is a certain menace to all its members if, through improper construction or defective ventilation, decomposing matter collects in the waste pipes and vitiates the atmosphere of the rooms. Many recurrent cases of tonsilitis are due to this cause. Even the ordinary stationary washstands may be a source of danger, especially in the bedroom, unless thoroughly ventilated and care exercised that the traps are not filled with decomposing matter. A physician of large experience in this city is so imbued with the danger of this form of plumbing that he condemns it _in toto_. When well constructed and well ventilated, however, they can not be the source of danger in the household. Tuberculosis, which is responsible for so enormous a mortality, frequently also affects the throat as well as the lungs. Although it usually originates within the chest, it sometimes finds its primary origin in the throat, and in a large percentage of cases the throat affection forms a complication of tuberculosis of the lungs. In spite of the numerous remedies which have been advocated for the cure of this disease, it must be admitted that our chief reliance is in proper nourishment and climatic effects, and that hygiene is the sheet-anchor which will eventually rescue us from this terrible foe of the human race.