We do not now advert to any of the other points connected with the history of gold on which our geological facts throw light. These illustrations are sufficient to show how rich in practical inferences and suggestions geological and chemical science is, in this as in many other special branches of mineral inquiry.
Nor need we say much in answer to our question,—“Why the ability to predict, as in the Australian case,” or generally to draw such conclusions and offer such suggestions and explanations, has remained so long unanswered, or been so lately acquired? Geology and chemistry are both young sciences, almost unknown till within a few years, rapidly advancing, and every day applying themselves more widely and directly to those subjects which effect the material prosperity and individual comforts of mankind. Knowledge which was not possessed before our day, could obviously neither be applied at all by ancient nations, nor earlier by the moderns.
To the consideration of the absolute extent and probable productive durability of the gold regions newly brought to light—of their extent and richness compared with those known in former times—and of their probable effects on the social and financial relations of mankind, we shall now turn our attention.
In the preceding part we have explained the circumstances in which gold occurs—the geological conditions which appear to be necessary to its occurrence—and where, therefore, we may expect to find it. But no conditions chemical or geological at present known are able to indicate—a priori, and apart from personal examination and trial—in what quantity the precious metal is likely to occur, either in the living rocks of a gold-bearing district, or in the sands and gravels by which it may be covered. Yet, next to the fact of the existence of gold in a country, the quantity in which it is likely to occur, and the length of time during which a profitable yield may be obtained, are the questions which most interest, not only individuals on the spot, but all other countries to which the produce of its mines is usually sent, or from which adventurers are likely to proceed.
We have already remarked, that, in nearly all the gold regions which have been celebrated in past times, their mineral riches have been for the most part extracted from the drifted sands and gravels which overspread the surface. We have also drawn attention to the small amount of skill and intelligence which this extraction requires, and to the brief time in which such washings may be exhausted even by ignorant people. Most of our modern gold mines are situated in similar drifts. We may instance, from among the less generally known, those of Africa, from which are drawn the supplies that come to us yearly from the gold coast.
“Of all the African mines those of Bambouk are supposed to be the richest. They are about thirty miles south of the Senegal river; and the inhabitants are chiefly occupied in gold-washing during the eight months of dry weather. About two miles from Natakou is a small round-topped hill, about 300 feet high, the whole of which is an alluvial formation of sand and pulverised emery, with grains of iron ore and gold, in lumps, grains, and scales. This hill is worked throughout; and it is said the richest lumps are found deepest. There are 1200 pits or workings, some 40 feet deep—but mere holes unplanked. This basin includes at least 500 square miles. Forty miles north, at the foot of the Tabwara mountains, are the mines of Semayla, in a hill. This is of quartz slate; and the gold is got by pounding the rock in large mortars. In the river Semayla are alluvial deposits, containing emery impregnated with gold. The earth is washed by the women in calabashes. The mine of Nambia is in another part of the Tabwara mountains, in a hillock worked in pits. The whole gold district of Bambouk is supposed to extend over 10,000 square miles.
“Close to the Ashantee country is that of the Bunkatoos, who have rich gold workings, in pits at Bukanti and Kentosoe.”—(Wyld, p. 44.)
From this description we see that all the mines in the Senegal country are gold-washings, with the exception of those of Semayla, to which we shall hereafter allude. No skill is required to work them; and should European constitutions ever permit European nations to obtain an ascendancy in this part of Africa, such mines may be effectually exhausted before an opportunity is afforded for the application of European skill. And so in California and Australia, should the gold repositories be all of the same easily explored character, the metal may be suddenly worked out by the hordes of all classes who have been rushing in; and thus the influence of the mines may die away after a few brief years of extraordinary excitement.
When California first became famous, the popular inquiry everywhere was simply, what amount of immediate profit is likely to be realised by an industrious adventurer? What individual temptation, in other words, is there for me or my connections to join the crowd of eager emigrants?
Passing over the inflated and suspicious recitals which found their way into American and European journals, such statements as the following, from trustworthy sources, could not fail to have a most stimulating effect—