The gold carried in rocks and veins is sometimes in a crystalline form, but in the majority of instances this is not very clearly defined, though with the smaller particles the edges of the crystals are more apparent; often that which appears to the unaided eye to be a thread or film of gold is, upon microscopic examination, discovered to be an aggregation of more or less dislocated minute crystals one built upon the other. In fact the more closely the occurrence of gold is examined the stronger is the evidence of its deposition from solution in separate and minute particles.
Another form in which gold occurs, far more widespread, and of incalculably greater aggregate value, than any other yet known, is the gold carried in the waters of the ocean this is not just now available for general circulation. That gold is present in all sea water, and may be determined easily, is not a matter of dispute ; it is held in solution, presumably in the form of bromides and iodides and is estimated that it is present to the extent of nearly one grain to the ton of water. The early alchemists seem to have stumbled across some traces of this fact in their search after the secret of transmutation. As might be expected, their notions on the subject were extremely visionary and indistinct, and were first given to the world in 1350 by the monk Odomar, who stated that the salt of the sea was the mercury of the philosophers or chief ingredient to be made use of in the composition of the wonderful stone which was to turn all that it touched into gold.
Gabriel de Chataigne, the Grand Almoner of Louis XIII., seems to have been more fortunate, for he states that he himself saw transmutation effected by a stone prepared with sea salt, and some report of this statement no doubt inspired Becher, in the proposal which he made in 1669 to the States General of Holland, to turn the dunes into gold, his offer, according to him, after the favorable report of a committee of chemists, being only rejected on account of the low state of the Dutch exchequer. Those curious in such survivals will find a series of experiments, intended to show the possibility of the transmutation of metals, set out at length in the report of a M. C. Theodore Tiffereau to the French Academy in 1854. If M. Tiffereau really did succeed in producing traces of gold by any such process as he describes, his success would seem to be due to the fact that he employed sea-salt as one of his ingredients.
Native gold is almost always found alloyed with a proportion of silver; this varies so greatly in different localities that no general statement can be made to indicate the proportion; but the higher the proportion the more closely to the forms approach those of native silver. Rhodium, palladium, mercury, copper, iron, and bismuth are amongst the other metals with which gold is found naturally alloyed; in some deposits it occurs with tellurium, and bismuth in what appears to be a definite chemical combination. The theory of the formation of veins, and the occurrence of gold therein, also in unstratified rocks, although deeply interesting, is outside the purpose of this inquiry, as is also any record of observations concerning shoots of gold in veins, saddle-back veins, for the reason that to touch upon these questions would only result in incompleteness, and to enter thoroughly into an investigation would lead into so many by-paths.
