Domestic science (Johnson, for schools and homes)

The tables given will serve somewhat as a guide to the housewife in the seclection of the daily menus for her family. Comparison of the Fuel (Heat and Energy Pro- ducing) Values of Some Common Food-Stuffs. Fats and Carbo-hydrates. Butter, ■^■BHBHBBHBBHBBHH^^H Oatmeal, JB^HBHBSBBmHI Sugar, Rice, White Flour, Cornmeal, Beans, Beef, rib. Beef, loin. White bread, Mutton, leg. Beef, round, Eggs, Ham, smoked, ■■§ Milk, unskimmed, ■■ Codfish, dressed, IBl Potatoes, BH Oysters, HI Milk, skimmed, fli Fig. 27. Based on the Govt. Analysis, U. S. Agricultural Dept 94 DOMESTIC SCIENCE C Digestion, and the Digestibility of Foods. The Digestive Processes begin in the mouth; where the foods are masticated by the teeth and mixed with the fluids from the Salivarg Glands and from the mucuous lining of the mouth. Fig. 28. The Salivary Glands. a. The right sublingual gland. b. The right submaxillary gland. c. The right parotid gland. The ducts leading from these glands to the mouth are also shown. The Salivary Glands are placed in pairs, one of each pair being situated on each side of the mouth. The fluid from these glands is called Saliva; and it is this fluid that performs the chemical changes on the foods, which are a part of the process of digestion. The fluid from the mucuous lining of the mouth performs no chemical changes in the foods; its work is to moisten the mouth and throat, to assist in mixing the saliva thoroughly with the food, and to soften starch grains so that they will burst and permit of APPENDIX 9S the action of tKe saliva. The digestive glandi may be con- sidered as little pouches, with mouths partially, or quite closed when no food is in process of mastication; but which open more or less, as soon as the delicate nerves of the tongue are touched by food or other substances placed in the mouth; and the flow may be started by simply the chewing motion of the jaws; and, also, by odors of foods, which strike the olfactory nerves, of the nose, and eflFect the nerves of the mouth through reflex action. Further, and what is still more wonderful, the thought of food, when one is hungry, will serve to cause the glands to pour their con- tents into the mouth; and sudden emotions, such as great joy, sorrow, or fear may relax or contract the muscles that control the mouths of the ducts of the salivarg glands and the mucuous glands of the mouth, and thus cause too great or too scant a flow of these fluids. Sometimes a frightened person finds himself suddenly unable to swallow, because of the dryness of the mouth and throat. The importance of the healthful action of all the digestive glands can scarcely be overestimated. These glands of the diff^erent digestive organs vary much in the amount of fluid secreted daily from the blood, and again returned to the blood in the processes of absorption and circulation, as shown by the following: Amount of Daily Secretions by the Different Digestive Glands. 1. Glands of the mouth, 1 to 3 pts. 2. Glands of the stomach, 10 to 20 pts. 8. Glands of the liver, 2 to 3 pts. It has been found difficult to estimate the amount of digestive fluids secreted by the intestinal glands.