I had advised them to make their first search in that spot for this reason: that, as the precious stones had there settled in the largest numbers, from their superior gravity, it was natural to conclude that, if gold should exist, it would, from its gravity, be somewhere below the precious stones or in their vicinity.
>From the facility with which it has been discovered, it is impossible to form an opinion as to the quantity or the extent to which it will eventually be developed. It is equally impossible to predict the future discoveries which may be made of other minerals. It is well known that quicksilver was found at Cotta, six miles from Colombo, in the year 1797. It was in small quantities, and was neglected by the government, and no extended search was prosecuted. The present search for gold may bring to light mineral resources of Ceylon which have hitherto lain hidden.
The minerals proved to exist up to the present time are gold, quicksilver, plumbago and iron. The two latter are of the finest quality and in immense abundance. The rocks of Ceylon are primitive, consisting of granite, gneiss and quartz. Of these the two latter predominate. Dolomite also exists in large quantities up to an elevation of five thousand feet, but not beyond this height.
Plumbago is disseminated throughout the whole of both soil and rocks in Ceylon, and may be seen covering the surface in the drains by the road side, after a recent shower.
It is principally found at Ratnapoora and at Belligam, in large, detached kidney-shaped masses, from four to twenty feet below the surface. The cost of digging and the transport are the only expenses attending it, as the supply is inexhaustible. Its component parts are nineteen of carbon and one of iron.
It exists in such quantities, in the gneiss rocks that upon their decomposition it is seen in bright specks like silver throughout.
This gneiss rock, when in a peculiar stage of decomposition, has the appearance and consistency of yellow brick, speckled with plumbago. It exists in this state in immense masses, and forms a valuable buildingstone, as it can be cut with ease to any shape required, and, though soft when dug, it hardens by exposure to the air. It has also the valuable property of withstanding the greatest heat; and for furnace building it is superior to the best Stourbridge fire-bricks.
The finest quality of iron is found upon the mountains in various forms, from the small iron-stone gravel to large masses of many tons in weight protruding from the earth's surface.