Protein is the tissue builder; heat and energy are derived largely from the non-nitrogenous foods. A Calorie (large) is the unit of heat required to raise one kilogram of water to 1° C. The full value of a food is ascertained by means of the calorimeter, or apparatus used to determine the specific heat of substances, or the amounts of heat evolved or absorbed in various physical and chemical changes. Calorimeters take very diverse forms, varying from quite simple vessels to highly complex apparatus, according to the particular kind of determination to be carried out in them. (13) The time necessary for satisfying complete body needs and appetite daily, when the habit of attention, appreciation and deliberation have been installed, is less than half an hour, no matter how divided as to number of rations. This necessitates industry of mastication, to be sure, and will not admit of waste of much time between mouthfuls. (14) Ten or fifteen minutes will completely satisfy a ravenous appetite if all conditions of ingestion and preparation are favourable. (15) Both quantitive and qualitive supply of saliva are important factors; but attention to these fundamental requirements of right eating soon regulates the supply of all of the digestive juices, and in connection with the care recommended above, ensures economy of nutrition and, probably, immunity from disease. CHAPTER V WHAT IS PROPER MASTICATION? Not Excessive Chewing--Gladstone's Advice--Salival Action on Starch Foods Notwithstanding the fact that Fletcherizing stands for tasting as the important thing to accomplish before food is swallowed, and that biting, chewing, or masticating is merely a means to secure the end of thorough tasting, nine-tenths of all who know anything about the claims for Fletcherizing insist on thinking that it merely means "excessive mastication." The National Food Reform Association of England, in a bulletin giving advice concerning the feeding of school children, intended to be posted in school-rooms and private dining rooms, speak of Fletcherizing in its ideal practice as "Excessive Mastication." This is just what Fletcherizing is not. The very essence of the method of performing the personal responsibility is avoiding excess of anything, excessive or laboured chewing among the rest. There is little if any harm in keeping food in the mouth as long as possible, and I believe that it is impossible to have too much saliva mixed with it when it is swallowed, because when it is properly tasted and insalivated it is almost impossible to hold it back from the food gate at the back of the mouth. There is always suction there ready to draw welcome nourishment in when it is ready, and readiness touches a button, electrically relieving the muscular springs that close the gate tightly during tasting, and, literally a "team of horses could not hold it."