Labyrinth, 222 Lachrymal canals, 201 gland, 201 Lacteals, 96 Absorption by, 96 Lactic acid in gastric juice, 92 Lactometer, 68 Large intestines, 94 Laryngoscope, 231 Larynx, 125, 228 Production of the voice in the, 126, 228 Lens, crystalline, 209 Ligaments, 19 Light, theory of, 197 Lime in the bones, 16 in the food, 56 Importance of, 56 Liver, 95 Secretion of the, 95 Locked jaw, 169 Long-sight, 212 Lungs, 123 Capacity of, 130 Structure of, 125 Lymph, 97 Lymphatic vessels, 97 M. Magendie, on pain, 181 Magnesia, Compounds of, in food, 57 Malleus, 220 Marrow of the bones, 17 Mastication, 82 Importance of, 88, 89 Meats, 68 The cooking of, 69 The preservation of, 69 Membrane of the tympanum, 219 Medulla oblongata, 154 Function of the, 171 Microscope, 236 The value of the, 236 Simple, 237 Compound, 239 The use of the, 239 {268} Milk, 68 Composition of, 68 Specific gravity of, 68 Milk-teeth, 82 Mucous membrane of air passages, 127 Muscles, 25 Function of the, 25 Flexion and extension of, 26 Voluntary and involuntary, 26 Muscular contraction, 27 fibres, 25 sense, 188 Myopia 212 N.