HOT SPRINGS.
Mineral and hot springs have been discovered in many districts. In taste the waters mostly resemble those of Harrowgate, being nauseous to the palate.
EARTH OIL.
The oleum terrae, or earth oil, used chiefly as a preservative against the destructive ravages of the white-ants, is collected at Ipu and elsewhere.*
(*Footnote. The fountain of Naphtha or liquid balsam found at Pedir, so much celebrated by the Portuguese writers, is doubtless this oleum terrae, or meniak tanah, as it is called by the Malays.)
SOFT ROCK.
There is scarcely any species of hard rock to be met with in the low parts of the island near the seashore. Besides the ledges of coral, which are covered by the tide, that which generally prevails is the napal, as it is called by the inhabitants, forming the basis of the red cliffs, and not infrequently the beds of the rivers. Though this napal has the appearance of rock it possesses in fact so little solidity that it is difficult to pronounce whether it be a soft stone or only an indurated clay. The surface of it becomes smooth and glossy by a slight attrition, and to the touch resembles soap, which is its most striking characteristic; but it is not soluble in water and makes no effervescence with acids. Its colour is either grey, brown, or red, according to the nature of the earth that prevails in its composition. The red napal has by much the smallest proportion of sand, and seems to possess all the qualities of the steatite or soap-earth found in Cornwall and other countries. The specimens of stone which I brought from the hills in the neighbourhood of Bencoolen were pronounced by some mineralogists, to whom I showed them at the time, to be granite; but upon more particular examination they appear to be a species of trap, consisting principally of feldspar and hornblende, of a greyish colour and nearly similar to the mountain stone of North Wales.
PETRIFACTION.
Where the encroachments of the sea have undermined the land the cliffs are left abrupt and naked, in some places to a very considerable height. In these many curious fossils are discovered, such as petrified wood, and seashells of various sorts. Hypotheses on this subject have been so ably supported and so powerfully attacked that I shall not presume to intrude myself in the lists. I shall only observe that, being so near the sea, many would hesitate to allow such discoveries to be of any weight in proving a violent alteration to have taken place in the surface of the terraqueous globe; whilst, on the other hand, it is unaccountable how, in the common course of natural events, such extraneous matter should come to be lodged in strata at the height perhaps of fifty feet above the level of the water, and as many below the surface of the land.
COLOURED EARTHS.