644 



Index. 



SALT 



Salt deposited by the sea, 61 



— in volcanic strata, 61, 86 



— lakes of, in craters, 127 



— with upraised shell, 267, 273 



— lakes of, 308 



— purity of, in salt lakes, 311 



— deliquescent, necessary for the 

 preservation of meat, 311 



— ancient formation of, at Iqui- 

 que, 579 



— ancient formation of, at S. Lo- 

 renzo, 579 



— strata of, origin of, 580 

 Salts, superficial deposits of, 302 

 Sand-dunes of the Uruguay, 191 



— of the Pampas, 193 



— near Bahia Blanca, 194, 215 



— of the Colorado, 195, 216 



— of S. Cruz, 204 



— of Arica, 265 

 Sandstone of Brazil, 169 



— of the Cape of Good Hope, 169 



— platforms of, in New South 

 Wales, 147, 169 



Sarmiento, Mount, 445 



Schmidtmeyer on auriferous detri- 

 tus, 581 



Schomburghk, Sir R., on sea- 

 bottom/226 



— on the rocks of Guyana, 424 

 School, radiating, 166 

 Scotland, sloping terraces of, 295 

 Scrope, Mr. P., on silex in trachyte, 



18 



— on obsidian, 72 



— on laminated trachyte, 74, 76, 80 



— on sphserulites, 76 



— on separation of trachyte and 

 basalt, 133 



Sea, nature of bottom off Pata- 

 gonia, 214 



— power of, in forming valleys, 

 300 



iSea cliffs, formation of, 228 

 Seal, Mr., model of St. Helena, 



229 

 Seale, Mr., geognosy of St. Helena, 



85 



— on embedded birds' bones, 102 



— on extinct shells of St. Helena, 

 102 



SILICA 



Seale, Mr., on dikes, 103, 104 

 Sebastian Bay, tertiary formation 



of, 385 

 Sedgwick, Prof., on concretions, 69 



— on cleavage, 462 



Septaria in concretions in tuff, 56 

 Serpentine of Copiapo, 552 

 Serpulas, on upraised rocks, 269 

 Seychelles, 141 



Shale-rock, of the Portillo Pass, 

 489 



— of Copiapo, 559 



Shells, particles of, colours of, 

 affected by light, 61 



— particles of, drifted by the wind 

 at St, Helena, 99 



— land, extinct at St. Helena, 101 



— from Van Diemen's Land, 154, 

 176 



— from St. Jago, 171 



— fossil, from St. Helena, 173 



— upraised, state of, in Patagonia, 

 208 



— elevated, too small for human 

 food, 241 



— transported far inland, for food, 

 242 



— upraised, proportional numbers 

 varying, 249, 267 



— upraised, gradual decay of, 265, 

 267, 273 



— upraised, absent on high plains 

 of Chile, 287 



— upraised, near Bahia Blanca, 

 325 



— preserved in concretions, 391, 

 395 



— li\ iDg and fossil, range of, on 

 west coast, 410, 413 



— living, different on the east and 

 west coast, 219 



Shelly matter deposited by the 



waves, 60 

 Shingle of Patagonia, 219 

 Siau, M.,on ripples, 151 



— on sea bottom, 225 

 Signal Post Hill, 11, 17, 18 

 Silica deposited by steam, 29 



— laige proportion of, in obsi- 

 dian, 69, 73 



— specific gravity of, 1 37 



