The workings of this mine extend at least seventy fathoms in length under the bed of the sea; and in these caverns of darkness are many human beings, for a small pittance, and even that of a precarious amount, constantly digging for ore, regardless of the horrors which surround them, and of the roar of the Atlantic ocean, whose boisterous waves are incessantly rolling over their heads. We should feel pity for the wretch who, as an atonement for his crimes, should be compelled to undergo the task which the Cornish miner voluntarily undertakes, and as cheerfully performs; yet such is the force of habit, that very rarely does any other employment tempt him to forsake his own; the perils of his occupation are scarcely noticed, or if noticed, are soon forgotten. The _Lode_[60] of the mine may be seen _cropping out_, in the group of rocks beneath the engine. The ore is the grey and yellow sulphuret of copper, mixed with the oxide of tin,[61] of which _she_[62] has already "_turned up_" a sufficient quantity to afford a very handsome premium to the adventurers. In the grey sulphuret of this mine, _purple copper ore_, of the kind called by the Germans "_Buntkupfererz_," is frequently met with. Besides which, a great number of interesting minerals may be collected, as several varieties of _Jasper_; _arborescent native Copper_; _Jaspery iron ore_; _Arseniate of Iron_, which until it was discovered in the _Crown lode_ of Botallack, was unknown in St. Just. It is of a brown colour, and is crystallized in cubes. _Sulphuret of Bismuth_, imbedded in _Jasper_; beautiful _specular iron ore_; _hæmatitic Iron_; and the _hydrous oxide of iron_, in prisms terminated by pyramids, and which was supposed by the Count de Bournon to contain _Titanium_. The picturesque rocks of this district may be considered as composed of _Hornblende rock_, which will be found to alternate with slate. The contorted appearance of the former in the vicinity of Botallack is very singular, and will admit of much speculation. The _Crown rocks_, to which the mineralogist must not neglect to descend, consist of extremely compact _Hornblende rock_, in which occur numerous veins and beds of different minerals; viz. _veins of Garnet rock_, with numerous imbedded crystals, being at one part almost a foot in width; _Magnetic Iron Pyrites_, massive, in beds, near the engine; its colour is bluish-grey, and it is called by the workmen _Spelter_, who mistake it probably for _Blende_, which latter mineral also occurs here in considerable quantities. In a part of the rock, which is almost inaccessible, there is a vein of _Epidote_, distinctly crystallized, and about six inches wide. The miners, however descend the fearful precipice without any difficulty, in order to collect specimens for the inquisitive visitant. _Axinite_ also occurs in veins, or perhaps in beds; _Thallite_, _Chlorite_, _Tremolite_, and a black crystallized _Schorl_, in which the late Rev. William Gregor detected six per cent.