The first step for the teacher or mother in reading the index for colds is to look into the coat closet for evidence of warm clothing and overshoes, then to note whether the children put them on when they go out for lunch or recess. Whether "cold" settles in the nasal passages, ear, or stomach depends upon which is the weak spot. Draughts, thin soles, wet soles, exposure when perspiring, may be the immediate cause of the nutritional or respiratory disturbances that give cold germs a foothold. Adenoids, diseased teeth, inflamed ears, may furnish the food supply. "There is no use treating children and sending them on fresh-air trips as long as they have nutritional and digestive disturbances due to bad teeth, or colds due to adenoids," said a physician when examining a party of children for a summer outing. The great preventive measure to be taken for catching diseases, colds, diseased glands,--in fact all germ diseases,--is the repeated cleansing of those portions of the human body in which germs may find lodgment,--the mouth, the nose, the eyes, and the ears. In caring for young infants great pains is taken to cleanse all the orifices daily, but as soon as the child washes himself this practice is usually abandoned. Washing these gateways is far more important than washing the surface of the body through which germs could not possibly gain entrance into the system except through wounds. Oftentimes the douching of the nostrils with salt water will stop a cold at once. The mouth is the most important place of all, and the teacher should take care of her pupils' mouths first and foremost. As bad teeth, enlarged tonsils, and adenoids harbor germs and putrescent matter that vitiate every incoming and outgoing breath, these defects should be immediately corrected. Are we coming to a time when a thorough house-cleaning in the mouth of every child will take place before he enters the schoolroom, preferably in the presence of the teacher? Two other "catching" diseases cause city schools a great deal of trouble,--trachoma and pediculosis (head lice). There are probably no two diseases more quickly transmitted from one person to another. Almost before their presence is known, all children of a school or all persons of a group have contracted them. When at college twenty men of my fraternity discovered almost at the same time that they had an infectious eye trouble; yet we thought we were using different towels and otherwise taking sanitary precautions. Last summer a Vassar graduate took a party of tenement children for a country picnic. She returned with head lice that required constant attention for weeks. What then may we expect of children who live in homes where there is neither water, time, nor privacy for bathing, where one towel must serve a family of six, where mothers work for wages away from home and see their children only before seven and after six?