MINES, METALS, GEMS, &C. Introductory 168 Diamond Mines 169 Gold and Silver Mines 178 Quicksilver Mines 193 Iron Mines 195 Copper Mines 204 Tin Mines 209 Lead Mines 211 Coal Mines 212 Salt Mines 223 PHENOMENA OF THE OCEAN. Introductory 230 Saltness of the Sea 231 Congelation of Sea-Water 234 Ice-Islands 235 Icebergs 244 Luminous Points in the Sea 245 Tides and Currents 246 CATARACTS AND CASCADES. Introductory 252 Falls of Niagara 253 Falls of the Montmorenci 270 The Tuccoa Fall 272 Falls of the Missouri 272 Catskill Falls 274 Trenton Falls 275 Waterfall of South Africa 275 Cataracts of the Nile 276 Cataract of the Mender 276 Other Cataracts 277 SPRINGS AND WELLS. St. Winifred’s Well 280 Wigan Well 282 Dropping Well at Knaresborough 283 Broseley Spring 284 Hot Springs of St. Michael 284 Hot Springs of the Troad 285 Other Springs 286 BITUMINOUS AND OTHER LAKES. Pitch Lake of Trinidad 290 Mud Lake of Java 291 Salt Lake of Utah 292