Seychelles.
Shells, colour of, affected by light. -from Van Diemen’s land. -land, extinct, at St. Helena. -particles of, drifted by the wind at St. Helena.
Shelly matter deposited by the waves.
Siau, M., on ripples.
Signal Post Hill.
Silica, deposited by steam. -large proportion of, in obsidian. -specific gravity of.
Siliceous sinter.
Smith, Dr. A., on junction of granite and clay-slate.
Spallanzani on decomposed trachyte.
Specific gravity of recent calcareous rocks and of limestone. -of lavas.