APPETITE is the most important factor in nutrition. This estimation is based upon evidence given more fully in the various appendices, but the measure of its importance may be briefly stated, as follows:— _First_ In its normal state, Appetite is a perfect indicator of the bodily need of nutriment and moisture, both as to quantity and as to the chemical elements required at the moment. _Second_ APPETITE is a creature of the mind and does not attach to a tissue. It can be as easily changed, from abnormal to normal, by suggestion, as can the mind itself, and is not like a solid, the form or habit of which has been set in a mould. Whoever has once experienced a bad oyster and has abhorred oysters ever after will substantiate this claim regarding the caprices of appetite. _Third_ APPETITE can be easily comprehended and read and the degrees of its satisfaction understood by simple attention and study for a brief period (vide Van Someren). _Fourth_ ATTENTION is necessary to create APPRECIATION, and appreciation is absolutely necessary to stimulate the secretion and flow of gastric and other digestive juices (vide Pawlow). _Fifth_ ANGER, or shock of any kind, and WORRY, or any of the pessimistic depressants, stop digestive activity and cause indigestion (vide Cannon). _Sixth_ MENTICULTURE should begin with its application to selection (through a normalised appetite) of nutriment for the body, and continue to aid digestion by right thinking. It is very easy to cultivate calm and fortify against surprise, shock, and anger if the nutrition of the body is carefully attended to. The physical and the mental equipments are beautifully reciprocal and necessary to each other in promoting MENTICULTURE. B The Mechanical and Chemical Physiology of Nutrition BUCCAL DIGESTION THROUGH MOUTH THOROUGHNESS Mouth treatment of food, which permits, aids, and includes insalivation (mixing with saliva), and which is both actively digestive in its functions and preparatory to final digestion, is the only _actual mechanical responsibility_ we have in our nutrition; and, in connection with favourable A conditions, insures perfect digestion. It has been so fully and clearly explained in some recent articles, “Observations on Mastication,” by Dr. Harry Campbell, F.R.C.P., physician to the Northwest London Hospital, printed in the “Lancet” of July 11th, 18th, 25th, and August 8th, 1903, that reference to the articles, reprinted herewith, is all that is necessary here. In giving attention to careful mouth-treatment of soft or liquid foods until they are absorbed by the Swallowing Impulse the best health and economic results are obtained. It should, at least, be tried.