Some one has said that to cap a badly exposed pulp is to create a slumbering volcano, and he might well have added that such volcanoes have but a limited time to slumber. Gentlemen, there are in our own country ten thousand volcanoes belching forth--not pure molten lava--but impure gases and putrescent matter of the most sickening character. The craters to these volcanoes are not found on the mountain top, but they are found in human mouths--in the antrum of Highmore, in the nasal passages, and externally on the face, neck, or even on the chest. When the pulp of a tooth is dead and confined within its bony walls an outlet is sought, and must be affected for the escape of impure gases arising from the decomposing pulp and for the putrescent matter associated with it. When thus confined its only way of escape is through the dental foramen, and into tissues adjacent thereto. The pressure thus brought to bear upon the bony walls surrounding the apex of the root will in time perforate it at its weakest point, and the poisonous matter is forced through the opening thus formed and into the soft tissues, which soon yield to the pressure, and the imprisoned mass of corruption is liberated. The pain and swelling now subsides, but a dangerous nuisance has been created. The channel formed from the apex of the root to an external opening will not close while it is used for the passage of foul matter and gases that will flow unceasingly from the pulp canal. The remedy of course is to remove the cause, and assist nature in affecting a cure, and to do this the pulp chamber must be opened, its contents removed, the canals cleansed and disinfected, the abscess healed, and the roots filled to the exclusion of all fluids and purulent matter. But how often this is not done. How many thousands of suffering mortals are to-day dragging out miserable lives because of these drainage tubes emptying themselves into the oral cavity--into the maxillary sinus or into the meatus of the nose. Such an abiding nuisance in the mouth cannot long exist without ruining health. But how few of the unfortunate sufferers realize the cause of their nervous irritability, their loss of appetite, their feeling of lassitude, their lack of energy, and their general prostration. And here let me say, that but few, in comparison to the number of these unfortunate sufferers seek relief at the hands of the dental practitioner. The patient is neither sick nor well, but debilitated and "good for nothing." The family physician is consulted, nervines and tonics are administered, but to no avail. The septic matter is vitiating the air that is breathed, and poisoning the food that is eaten. The saliva that is poured into the mouth from the various glands must mingle with this poisonous matter and carry it into the stomach.