When the gas that is smelled is part of an inward air current we recognize it as coming from the outside and call it an odor; when it is part of an outward current we call it a flavor. On account of the rapid fatigue of the sense of smell we are unconscious of the smell of our own breath, but can get fresh smells from within, and these come, practically always, from materials that have just been taken into the mouth. In comparison with taste flavor furnishes great variety of perception. As persons become connoisseurs in food their enjoyment depends more and more on flavor and less and less on taste. The sensation from spices is a combination of flavor with irritation of the tongue that is partly pain and partly touch. The sense of smell has evidently a two-fold use; it makes us aware that there is food in the vicinity, or sometimes that disagreeable things are near at hand; and it shares with taste the duty of enabling us to judge of the food as it is being eaten. Agreeable tastes, flavors, and odors add much to the enjoyment of life. Within reasonable limits it is well to cultivate this kind of enjoyment, for while there is no doubt that it can be overdone, as in the excessive lengths to which the decadent Romans went to gratify their taste and smell, neither is there any doubt that bodily health in general, and the bodily function of digestion in particular, benefit definitely from the kind of enjoyment that savory food and delightful odors bring. It is the duty of those charged with the responsibility of preparing and serving food to take pains that full advantage is taken of the possibilities present in what food is to be prepared. This does not mean expensive food; what it does call for is skillful handling of all food, whether cheap or costly.