One feature in the distribution of gold in the quartz lodes of Santo Domingo led to a most exaggerated opinion of their value when they were first mined by English companies. On the hills, near the outcrops of the lodes, the ore was in some places exceedingly rich. One thousand ounces of gold were obtained from a small patch of ore near the surface of the Consuelo lode, and at Santo Domingo, San Benito, San Antonio, and Javali lodes, very rich ore was also discovered within a few fathoms of the surface. When, however, these deposits were followed downwards, they invariably got poorer, and at one hundred feet from the surface, no very rich ore had been met with. Below that, when the works are prosecuted still deeper, there does not appear to be any further progressive deterioration in the value of the ore, and it varies in yield from two to seven pennyweights of gold per ton, upon which yield further depth does not seem to have any effect. The cause of these rich deposits near the surface does not appear to me to be that the lodes originally, before they were exposed by denudation, contained more gold in their upper portions than below, but to be the effect of the decomposition and wearing down of the higher parts, and the concentration of the gold they contained in the lode below that worn away. We have seen that in the decomposed parts of the lode the gold exists in loose fine grains. During the wet season water percolates freely from the surface down through the lodes, and the gold set free by the decomposition of the ore at the surface must be carried down into it, so that in the course of ages, during the gradual degradation and wearing away of the surface, there has, I believe, been an accumulation of the loose gold in the upper parts of the lodes from parts that originally stood much higher, and have now been worn away by the action of the elements.