day."--(Chapin: The Sources and Modes of Infection, p. 188.) ORAL HYGIENE.--Cleanliness and proper care of the mouth and teeth can hardly be over emphasized. Their bearing upon health is direct. Long ago it was recognized that persons with decayed or missing teeth frequently suffered from dyspepsia, a natural result of inability to masticate properly, but only within recent years has it been realized that decayed teeth give rise to many other diseased conditions. Bacteria are constantly present in the mouth. If the mucus of the mouth is not removed, it forms a sticky coat upon the surfaces of the teeth and gums. In this bacteria collect, and pus or matter may also be formed, which, if carried by the blood to other parts of the body, may cause digestive troubles, rheumatism, and diseases of heart and kidneys. (See Dr. T. B. Hartzell, Health News, Oct., 1915, "The Importance of Mouth Hygiene and How to Practise it.") To keep the mouth and teeth healthy they must have: 1. Proper use. 2. Proper care. 3. Proper treatment. 1. Teeth, like other parts of the body, need exercise. Foods that require a considerable amount of chewing should be included in the diet. Such food is needed by children as soon as their first teeth have come, but care must be exercised to see that the food is actually chewed before it is swallowed. 2. A good brush should be provided. The stiffness of the bristles should be regulated according to the individual. The brush should be thoroughly rinsed after using, and discarded as soon as it is worn. Dental floss is generally needed to remove particles that have lodged between the teeth. Brushing the teeth by passing the bristles across them is not efficacious. They should be brushed not across but with the cracks, as a good housewife sweeps a floor. "In the light of recent investigation conducted by some of the leading students of mouth hygiene, the most effective way to use the toothbrush is to place the bristles of the brush firmly against the teeth, applying firm pressure, as though trying to force the bristles between the teeth, using a slight rotary or scrubbing motion.... After a little practice the user of this method will be surprised at the results obtained. Care should be used to go over all the surfaces of the teeth in this manner."--(See Dr. W. G. Ebersole. "The Importance of Mouth Hygiene and How to Practice it," Health News, Oct., 1915.) After brushing the teeth, the mouth should be rinsed by forcing lukewarm water about the teeth, using all the force that can be brought to bear by the cheeks, lips, and tongue.