Hunger, necessity of the sense of, as a warning that food is required, 10, 218. An affection of the brain, 12. Allayed by narcotics, 14, 15. Influenced by mental emotions, 16. By what condition of the stomach is it excited?, 17. Felt keenly when the body is in need of repair, 19, _et seq._ Sharpened by muscular exercise, 19, 21. Its absence during fever a wise arrangement, 31. Susceptible of being trained, 32. Error of confounding it with taste, 33. Morbid cravings of hunger when food is not required, 34. Instances of extraordinary voracity, 35. Periodicity of, 189. Does not return till stomach has been for some time empty, 190. Hydra, stomach of the, 63. Ices and ice-creams hurtful after a meal, 309. Ice useful in warm weather when used with caution, 311. Examples in Italy and Virginia, 311. Ileum, 177. Indigestion, why prevalent among sedentary persons, 29, 301. Injures the teeth, 47. Often beneficial in warding off more serious diseases, 245. Caused by grief, anxiety, and over-study, 126, 297. Infants, food proper for, as indicated by the state of their teeth, 45. Diet of, 232, 256. Prevalent errors in the treatment of, 233. Proper time for weaning them, 263. See _Children_. Infection, why most easily caught before breakfast, 194. Injection of food into the bowels, 164. Insalivation of food, 49. Intemperate eating a prevalent cause of disease, 222. Drinking, 319. Intestines described, 154. See _Bowels_. Jejunum, 177. Jelly, 125. Kitchiner, Dr, quoted on digestion, 120, 190. Lacteals, 62, 163. La Trappe, diet of the monks of, 191. Laughter aids digestion, 127, 297. Laxatives, 158, 238, 326. Lent, rapid recovery of the sick in Catholic countries during it, 222. Liquid food, 79, 117, 139, 281, 304. Too cold or hot injurious, 308, 312. Different kinds in use, 314. Literary men, indigestion of, 209, 297. Liver, its function, 173. Londe, Dr, quoted on the digestion of vegetables, 182. On the diet of infants, 235. Luncheon, 203. Lungs, how wasting of the body is produced by their disease, 167. See _Consumption_. Lymphatics, 164. Mastication, process of, described, 40. Its apparatus various in different animals according to the nature of their food, 50. Bad effects when mastication is incomplete, 51. Purpose of, 53.