CHAMBERS'S INFORMATION FOR THE PEOPLE. 



HYDRAULICS, 225 ; hydraulic press, 226. 

 Hydrocarbons, in Chemistry, 323 ; in Lighting, 



49i. 493- 



Hydrocephalus (Gr.), the disease commonly called 

 water in the head, 777. 



Hydrochloric acid (spirit of salt), 307. 



Hydrocyanic acid, or Prussic acid, 335, 783. 



HYDRODYNAMICS, 233-236. 



Hydrogen, chemically considered, 320, 



Hydrometer (Gr. hydor, water, metron, a measure), 

 232. 



Hydrophidaj (water-serpents), in Zoology, 164. 



Hydrophobia, the disease of canine madness, 

 marked by a dread of water, as the name radi- 

 cally implies ; in diseases of dogs, 695. 



HYDROSTATICS, 225-232 ; hydrostatic bellows, 

 226 ; paradox, 225. 



Hydrothorax, 774. 



Hydrozoa, class, in Zoology, 135. 



Hygrometer, principles and construction of, 35. 



Hymenoptera (membrane- winged), an insect order, 

 148. 



Hystricidas, Porcupine family, 187. 



Ibis (TantaKnce), in Zoology, 170. 



Ichneumon (Herpestes Pharaonis), in Zoology, 1 86. 



Ichneumon flies, in Entomology, 148. 



Ichthyolite (Gr. ichthys, a fish, and lithos, a stone), 

 a fish, or any part of a fish, found in a fossil 

 state, is termed an ichthyolite, 28. 



Ichthyology, that branch of zoological science 

 which treats of fishes, their structure and varie- 

 ties, 155-161. 



Ichthyopsidae, Huxley's group of fishes and am- 

 phibia, 155. 



Ichthyosaurus (Gr. ichthys, a fish, sauros, a lizard), 

 a remarkable family of secondary fossil reptiles, 

 30, 1 66. 



Ides, in the Roman calendar, 290. 



Igneous agency, one of the elevating causes in 

 geology, such as volcanoes, earthquakes, &c. 20. 



Ignis-fatuus, 48. 



Iguanidae, family of Lizards, 165. 



Iguanodon, an extinct fossil reptile, 166. 



Ileum, in Human Physiology, 116. 



Imago, last stage of insect metamorphoses, 146. 



Impenetrability, a property of matter, 193. 



Implacentalia, section in Geology, 177. 



Imponderables, a term applied to light, heat, 

 electricity, magnetism, as being without weight. 

 They are properly not distinct substances, but 

 affections or motions of the molecules of sub- 

 stances. See Heat and Electricity. 



In-arching, practice of, in Gardening, 577. 



Incandescence, the state commonly called a white 

 heat, 491. 



Inclined plane, in Mechanics, 214. 



Incubus, or nightmare, cause of, 730. 



Indestructibility, a property of matter, 193. 



Indian architecture, 777. 



Indian hemp, 371. 



India-rubber, nature and applications of, 383. 



Indicator, the, machine for measuring work done 

 by an engine, 432. 



Indiction, the, in Chronology, 292. 



Indigo, colouring-matter, preparation of, 342. 



Induction, electrical, 262. 



Induction coil, in Electricity, 282. 



Inertia, a property of matter, 194. 



Infusoria, class in Zoology, 134. 



Ingot, the term applied to small masses or bars of 



812 



the precious metals, either for coining or for 

 exportation, 404. 



Ink, writing, printing, 335, 348. 



INLAND CONVEYANCE, 433-448. 



Innervation, in Human Physiology, 123. 



Inorganic, anything without natural vitality, or pos- 

 sessing no organs of growth or reproduction, 129. 



Insalivation, in Human Physiology, 114. 



Insectivora (literally, insect-eaters), order in 

 Zoology, 1 88. 



Insects (Lat. insecta), 145 ; metamorphosis of, 146. 



Insessores, or Perching-birds, order in Zoology, 

 173- 



Insulated (Lat. insula, an island), in Architecture, 

 applied to any detached or isolated building; 

 in Electricity, 261. 



Intercalary, a day introduced every fourth or leap 

 year into the calendar, 291. 



Intestines, 116, 122, 770. 



Inulin, 331. 



Iodine, one of the elementary bodies, 307, 325. 



Ionic order, in Grecian architecture, 470. 



Iridium, one of the metallic elements, 416. 



Iris, in Anatomy, the contractile circle which sur- 

 rounds the pupil of the eye, so called because, 

 like the rainbow (Gr. Iris), it varies in colour, 

 125. 



Iron, in Chemistry, 307, 327 ; in Metallurgy, 405 ; 

 meteoric iron, 405 ; ores, 406 ; smelting of ore, 

 406 ; pig-iron, 407 ; cast-iron, 408 ; malleable 

 iron, 409 ; Bessemer's process, 409 ; statistics 

 of British iron manufactures, 411; magnetic 

 oxide of iron, 406. 



Irrigation, modes of, in Agriculture, 539. 



Irritability, in plants, 77 ; in animals, 130. 



Islands and continents of the globe, 53, 54. 



Isochronous, 203. 



Isoclinic lines and charts, in Magnetism, 260. 



Isotheral, isocheimal, and isothermal lines, in 

 Meteorology, 42. 



Isthmus, in Physical Geography, 52. 



Italian architecture, 476. 



Itch, disease of, how caused, 144. 



Jackal, family Canidse, in Zoology, 186. 



Jacquard-loom for figure-weaving, 381. 



Jade, nephrite, or axe-stone, 395. 



Jaguar (Felidce), 187. 



Jasper, a precious stone, 400. 



Jaundice, treatment of, 776. 



Jejunum, in Human Physiology, 116. 



Jet, its nature and uses, 389. 



Jets-d'eau, 233 ; in Supply of Water, 506. 



Journal or gudgeon, in Machinery, 219. 



Julian style, in Chronology, 291. 



Bungles of India, in Physical Geography, 59. 



upiter, the largest of all the primary planets, 7. 



urassic System, in Geology, 29. 



ute, in Textile Manufactures, 372. 



Kale and German greens, 550. 



Kangaroo, a marsupial family, in Zoology, 178. 



Kaolin, petuntze, or china clay, 359, 393. 



Karnac, temples of, 467. 



Karoos, in Physical Geography, 56, 59. 



Kelp, the ash of sea-weeds, 338. 



Kennel or dog-house, management of, 694. 



Kepler, laws of, in Astronomy, explained, 8. 



Kidney-bean, horticultural varieties of, 551. 



Kidneys, 122, 776. 



Kingfishers (Alcedinidce), 175. 



