In connection with the consumption of gold in the Territory, it may be remarked that none of the savage tribes of this part of Borneo seen ever to have made use of this metal notwithstanding their intercourse with Malays, and in a less degree with the Chinese, during at least several centuries past. I have never known an instance of a Sea-Dyak or Land-Dyak, a Kyan or Bakatan seeking gold on his own account, and manufacturing it into any description of ornament, however rude.
When we endeavour to trace out the origin of the gold in Sarawak, we find the immediate source of the metal, in the gravels and alluvial clays and in some of the clay-shales, which so thickly mask the older formations in N. W. Borneo, and out of thesembeds it is being swept continually by running water. It is evident however, that so far we have traced the source but a single step back; and the conclusion at which I have arrived, from observation of a considerable number of sections in different parts of the country, is that the auriferous strata of Sarawak Proper are derived immediately from the waste of siliceous and porphytic dykes, associated with the system of antimony and arsenic lodes developed in that locality. Similar strata however in other localities (the Batang Lupar washings for instance) appear rather to have been rearranged more than once; so much so, in fact, that the original home of the gold they bear can no longer be guessed with any approach to certainty: and the only clue to the problem is to be found in the circumstance that invariably in these latter districts there is evidence of considerable metamorphic action among the constituent rocks of the several localities. It is highly probable that much of this gold originally lay in quartz rock, as is the case in many places in Sumatra and in the Malay Peninsula, and may be the case to a limited extent in the less known parts of Sarawak; but even if auriferous reefs are discovered at a future day in accessible situations, it is more than doubtful whether they will afford a field for the European speculation, especially since an analysis of a quantity of the auriferous veinstone at Bau, by a competent European metallurgist, has failed to give such a result as to tempt further operations.
Silver and Arsenic:—Some years ago a lode of native arsenic was worked at Bidi in conjunction with the antimony at the same spot, but the mine was subsequently abandoned as the ore scarcely repaid the cost of export. Realgar and Orpiment were observed, but not in quantity; the former is found in traces in the Upper Rejang, a district wholly unexplored by Europeans, and in the Baram. Argentiferous arsenical ore also occurred at Bidi, and an attempt was made to extract the Silver and gold
