Mouth infection, due to the teeth, sees its most critical period during that of childhood and early youth, a period in which the mouth under present conditions is almost entirely without intelligent care. Children’s mouths, says Dr. Smith, are frequently veritable crucibles in which are generated chemical agents and compounds highly detrimental to the teeth themselves, and not less to the general health of the child. The poisons arising from decaying food particles and decaying teeth themselves, vitiated salivary and mucous secretions, germ life upon the teeth and gums, and breaths loaded with emanations from stagnant septic material, all with the high temperature of ninety-eight degrees, insinuate into the general circulation of the blood a constantly increasing infection, which will later on find expression in many diseased conditions, and often in chronic and fatal disorders. It may appear, as it commonly does, in stomach or kidneys, in lungs or nervous system, in heart, brain, or skin, in any organ or tissue, indeed, to which mouth toxins are directly or indirectly conveyed. Experience has shown that it is not only possible, but entirely practicable to arrest and prevent teeth diseases in the mouths of children, and at the same time to keep the mouth aseptic or free from germ life. Not only does an infected mouth work havoc to the body of which it is the vestibule, but it spreads disease about it. The original experiments of Koninger have shown that in a room where there is no current of air perceptible, a person coughing or sneezing can scatter germs to a distance of more than twenty-two feet. They are conveyed through the air by means of little droplets of saliva. These globules are microscopic balloons, having a bubble of air in the center, and remain in suspension but a short time. Ordinary breathing will scatter these droplets to a considerable distance, but, of course, their germ-carrying capabilities are most marked during coughing and sneezing. The more microbes the mouth contains the greater the danger of infection. Washing the mouth has the effect of decreasing the microbes of such diseases as diphtheria and consumption, and other bacilli susceptible of being scattered abroad in these salivary droplets. Placing the hand or a handkerchief over the mouth prevents the emanation of droplets charged with bacilli. So well is this fact of droplet germ infection recognized, that in many operating rooms no one present is allowed to speak during operations. Chronic headaches, neurasthenia, constipation, coughs and colds, and many other grave troubles, have all been helped and many times cured by “oral prophylaxsis” or proper mouth treatment.