Hair, pernicious effects of preparations to colour the, 181 Heliotrope. See Bloodstone. Hone, or whetslate, description and use of, 80 Hyacinth, description and uses of, 30 Hydrogen, 19 I. Inflammable air, 19 Ink, indelible, for marking linen, how made, 181 ——, sympathetic, how made, 222 Instantaneous light, matches and bottles for procuring, how made, 145 Iron, description and uses of, 190 ——, mines, account of, 190 ——, how extracted from the ore, 191 ——, cast iron, what, and uses of, 191 ——, wrought iron, how made, and uses of, 191 ——, how preserved from rust, 193 ——, native, account of extraordinary masses of, 197 ——, magnetic, or loadstone, description and uses of, 197 ——, white, what, 201 Iron pyrites, description and uses of, 198 ——, how to gild on, 172 ——, sulphat of. See Vitriol, green. J. Jade, description and uses of, 88 James’s powder, of what made, 217 Jargoon, description and uses of, 29 Jasper, description and uses of, 60 ——, various kinds of, 61 ——, agate. See Agate. Jet, description, properties, and uses of, 158 ——, imitation of, 160 K. Kaolin, what it is, and how made, 74 Ketton stone, description and use of, 114 L. Labrador felspar, description and uses of, 69 Lapis lazuli. See Azure stone. Lapis ollaris, description and use of, 90 Lazulite. See Azure stone. Lead, description of, 203 ——, how extracted from the ore, 218 ——, pig lead, what it is, 204 ——, ancient and modern uses of, 204 ——, injurious effects of leaden vessels, 204 ——, alloys and oxides of, 205 ——, silver, how obtained from, 178, 207 ——, white, how manufactured, and uses of, 205 ——, red or minium, how manufactured, and uses of, 206 ——, sugar of, 207 ——, how detected in wine, &c., 207 ——, pleasing experiment with, 207 Lead mines, account of, 203 Lemnian earth, how obtained and use of, 86 Lias, use of for multiplying drawings, 116 Lime, 17; how burnt, and various uses of, 97 —— water, how made, 98 Lime carbonat of, 99 Lime sulphat of, 117 Lime fluat of, 119 Limestone, description and uses of, 99 ——, primitive, 228 ——, transition, 232 Litharge, how made and uses of, 206 —— plaster, of what made, 206 Loadstone, description of, where found, and uses of, 197 Loam, description and uses of, 73 Looking─glasses, process of silvering, 176 Lunar caustic, what it is, and uses of, 181 Lydian stone, description and uses of, 53 M. Magnesia, how prepared and uses of, 125 Malachite, description and uses of, 188 Manganese, description of, how obtained, and uses of, 222