Next the gums, the alveoli, and the roots of the teeth must be examined, especially for the presence of erosion, tartar, and pyorrhœa alveolaris, this latter condition being evidenced by the welling-up of pus upon pressing the gums against the sides of the teeth.

If our examination of the mouth discloses anything likely to interfere with mastication the aid of the dentist should at once be sought, but every physician should be so far acquainted with disorders of the teeth as to be able to say, in the majority of cases, at all events, when this is necessary. I am convinced that far more illness than is generally supposed is attributable to dental defects, and this even among the more leisured classes. With regard to pyorrhœa alveolaris, it has to be remembered that it not only does harm by causing loosening, lengthening, and shedding of the teeth, and thus interfering with mastication, but also by contaminating the stomach and the blood and thus upsetting the digestion and causing constitutional diseases, such as anæmia and arthritis; and inasmuch as poisonous discharges from the nose, the naso-pharynx, the pharynx, and the tonsils may act in a similar way, these parts also should be inspected in connection with the examination of the teeth. In the dust-laden atmosphere of towns they are very liable to disease, and even when healthy are necessarily dirtied; some go so far as to advise all town dwellers daily to wash out the nasal passages and to gargle the throat; but, whatever may be thought of this, it is certain that under existing dietetic conditions special means are needed in order to keep the mouth and teeth clean. When man fed on raw food this was not necessary, the food itself and the copious flow of saliva, induced by prolonged mastication, effectually cleansing these parts; but, under present conditions, food tends to remain within the mouth, especially between the teeth and in their crevices, and therefore special means are needed to remove it. This is done by “cleaning the teeth” and by rinsing the mouth.

The tooth-brush.—Probably the ideal method of cleaning the teeth is that adopted by many primitive and not a few semi-civilised peoples—viz., rubbing them with a twig of wood which has been teased out at one end so as to form a sort of brush by means of which the teeth can be burnished and food dislodged from them. The modern tooth-brush requires to be used with great caution, as it is capable of doing much harm, not only by removing the mucoid film, which, according to Dr. Wallace, protects the teeth from corroding agencies,[28] but probably also by injuring the edge of the gum and the neck of the teeth, and thus setting up the condition known as “erosion.” Certain it is that some of the best sets of teeth I have encountered have been wholly unacquainted with the tooth-brush. In any case the brush should be employed with great care; it should be soft, and should always be drawn away from the gums both on the inner and outer aspect of the teeth towards the biting surface, as well as across the latter, never transversely across the outer surfaces, as so frequently is done. The object of these procedures is to dislodge any particles of food that may have collected between the teeth or in their crevices. For this purpose the toothpick may also be employed judiciously. In order to render the enamel of the teeth white it is better to rub each tooth carefully with some soft material, such as chamois leather, rather than to scrub them with a brush. Tooth-powders should not be used as a matter of routine, but only occasionally and for appearance rather than for cleanliness, and should consist of some simple non-irritant material. Antiseptic powders and washes are to be scrupulously avoided, for it is neither desirable nor possible to render the buccal cavity aseptic; myriads of bacteria flourish within it, many of which play a useful part as scavengers. The time of all others for cleaning the teeth is just before going to bed, so that the food shall not be allowed to decompose in the mouth during the night. There will then be no need to use the tooth-brush in the morning.

Rinsing the mouth.—The mouth should be rinsed out as a matter of routine after each meal and on rising, and care should be taken to do this before the early cup of tea, so as not to contaminate the stomach with the buccal secretions which have accumulated during the night. Inasmuch as raw vegetable food has a cleansing effect on the teeth, it is often a wise plan, especially in the case of children, to finish a meal with some kind of fruit, such as an apple or an orange. It hardly seems necessary to insist upon the necessity for keeping all artificial dentures thoroughly clean.

PROFESSOR PAWLOW’S DEMONSTRATIONS OF PSYCHIC INFLUENCE IN DIGESTION

[In presenting a theory of human alimentation involving mental or nervous as well as mechanical and chemical factors which influence it for good, it is not often that an author is able to enlist the assistance of a complete battery of scientific confirmation to fortify his own crude observations taken direct from personal experience in the study of natural requirements.

Professor Pawlow, with his marvellously skilful investigation of the workings of the digestive secretions, and Dr. Cannon of the Harvard Medical School, by aid of persistent and patient X-ray studies, explain how it is that earned appetite and thorough mouth-treatment of food are preliminary necessities of easy digestion, and that disturbance or shock of any sort during the process stop digestive proceedings and endanger health. They show also that when the mouth is used to do all that it can do in the work of digestion all the rest is easily accomplished by the Natural Automatic Processes within the body.

They both show that we have, each of us, a certain responsibility in the matter of right digestion and healthy nutrition, and that all this personal responsibility is located in the head, in the mind, and in the mouth, and that while the alimentation is proceeding it is a sacred duty to do our part right, according to the intelligence that these most valuable demonstrations teach.

Professor Pawlow has allowed publication of his lectures in Russian and German, and recently Professor W. H. Thompson of the Physiological Department of Trinity College, Dublin, has made an English translation which is issued by Charles Griffin & Company of London and J. B. Lippincott of Philadelphia.

The author has to express special gratitude to Professor Pawlow, Professor Thompson, Messrs Griffin and Lippincott for permission to reprint herein some entire lectures and extracts that bear especially on the practical understanding of our subject.