406 
TIBET. 
of heat sufficiently intense for such purposes. Thus situated, the most 
valuable discovery for them, would be that of a coal mine. In some 
parts of China bordering on Thibet, coal is found, and used as fuel. 
Tincal, the nature and production of which, we have only, hitherto, 
been able to guess at, is now well known, and Thibet, from whence 
we are supplied, contains it in inexhaustible quantities. It is a fossil, 
brought to market in the state in which it is dug out of the lake, and 
afterwards refined into borax by ourselves. Rock-salt is likewise found 
in great abundance in Thibet. 
The lake, from whence tincal and rock-salt are collected, is about 
fifteen days journey from Tissoolumboo, and to the northward of it. It 
is encompassed on all sides by rocky hills, without any brooks or 
rivulets near at hand; but its waters are supplied by springs, which 
being saltish to the taste, are not used by the natives. The tincal is 
deposited or formed in the bed of the lake, and those who go to collect 
it, dig it up in large masses, which they afterwards break into small 
pieces, for the convenience of carriage, exposing it to the air to dry. 
Although tincal has been collected from this lake for a great length of 
time, the quantity is not perceptibly diminished; and as the cavities 
made by digging it, soon wear out, or fill up, it is an opinion with the 
people, that the formation of fresh tincal is going on. They have 
never yet met it in dry ground, or high situations, but it is found in 
the shallowest depths, and the borders of the lake, which, deepening 
gradually from the edges towards the centre, contains too much water 
to admit of their searching for the tincal conveniently; but from the 
deepest parts they bring rock-salt, which is not to be found in shallows* 
