472 COMMERCIAL DESCRIPTION OF ty of silver, and generally, although not always, some copper. The gold of Banjar-laut, for exam- ple, usually contains in 100 parts — gold 90 parts, silver 4 parts, and copper H parts. The gold of Larak, in the same island, affords in 100 parts — gold 86 parts, silver 6 parts, and copper 8 parts. The gold of Pontianak in 100 parts contains 83 parts of gold, l6 of silv„r, and about 1 of copper. A small part of the gold of commerce of the Indian Islands is obtained by mining processes from veins and mineral beds ; some from washing the sand and mud of brooks and rivers ; but by far the greatest portion by washing deposites of gold in alluvial lands. The first mode is chiefly follow- ed by the more civilized native tribes ; the second principally by the savages ; and the third chiefly by the Chinese. Mining, conducted in veins and mineral beds, is pursued, as far as I know, in the island of Sumatra only. The principal mines are in the interior of the island, in the country of the Bataks and Menangkabao Malays. The mines are but petty excavations. The perpendicular shaft usually goes no deeper than five or six fathoms, when the operations are pursued laterally, the sides of the mine being supported by beams of wood. Iron crows, shovels, and mallets, are the only tools made use of. The practice of blasting the rock is not known, neither is the simple w^ter- wheel of the Chinese, the mine being kept clear
