for hot weather, IV 1134 three classes of, V 1147 the normal, V 1152 radical changes in, V 1152 make patient agree with, V 1153 during embryonic period, V 1156 FOR CHILDREN (ages 1 to 2 years), V 1174 special instructions regarding simplicity in feeding, V 1176-1177 in old age, V 1178 ---- importance of, V 1181 for normal athlete, V 1189 (summer) for athletes, V 1191 (winter) for athletes, V 1192 in climatic extremes, V 1193-1199 under normal conditions, V 1200 DIGESTION chemistry of, I 139 uses of, I 139 malt in, I 140 energy required in, I 161 mental influence upon, I 162 secretion of juices in, I 163 important rules to observe to insure good, I 164 experiments in, I 175 mechanics of, I 180 action of enzyms during, I 181 food prepared for, I 186 during sleep, I 188 how affected, I 188 x-ray experiment in, I 188 comparative, of cooked and uncooked grain, III 597 true interpretation of the word, III 630 necessity for thorough mastication an aid to, I 181 "bolting" of food in, I 181 secretion of enzyms in, I 182