measure instead of weight.

SULPHUR.

Sulphur (balerang), as has been mentioned, is abundantly procured from
the numerous volcanoes, and especially from that very great one which is
situated about a day's journey inland from Priaman. Yellow Arsenic
(barangan) is also an article of traffic.

SALTPETRE.

In the country of Kattaun, near the head of Urei River, there are
extensive caves (goha) from the soil of which saltpetre (mesiyu mantah)
is extracted. M. Whalfeldt, who was employed as a surveyor, visited them
in March 1773. Into one he advanced seven hundred and forty-three feet,
when his lights were extinguished by the damp vapour. Into a second he
penetrated six hundred feet, when, after getting through a confined
passage about three feet wide and five in height, an opening in the rock
led to a spacious place forty feet high. The same caves were visited by
Mr. Christopher Terry and Mr. Charles Miller. They are the habitation of
innumerable birds, which are perceived to abound the more the farther you
proceed. Their nests are formed about the upper parts of the cave, and it
is thought to be their dung simply that forms the soil (in many places
from four to six feet deep, and from fifteen to twenty broad) which
affords the nitre. A cubic foot of this earth, measuring seven gallons,
produced on boiling seven pounds fourteen ounces of saltpetre, and a
second experiment gave a ninth part more. This I afterwards saw refined
to a high degree of purity; but I conceive that its value would not repay
the expense of the process.

BIRDS-NEST.

The edible birds-nest, so much celebrated as a peculiar luxury of the
table, especially amongst the Chinese, is found in similar caves in
different parts of the island, but chiefly near the sea-coast, and in the
greatest abundance at its southern extremity. Four miles up the river
Kroi there is one of considerable size. The birds are called
layang-layang, and resemble the common swallow, or perhaps rather the
martin. I had an opportunity of giving to the British Museum some of
these nests with the eggs in them. They are distinguished into white and
black, of which the first are by far the more scarce and valuable, being
found in the proportion of one only to twenty-five. The white sort sells
in China at the rate of a thousand to fifteen hundred dollars the pikul
(according to the Batavian Transactions for nearly its weight in silver),
the black is usually disposed of at Batavia at a