Productions of Boutan and Thibet. 
without any brooks or rivulets near at hand ; but its waters are 
fupplied by fprings, which being faltifh to the tafte are not 
ufed by the natives. The tincal is depofited or formed in the 
bed of the lake; and thofe who go to colled]: it, dig it up in , 
large maffes, which they afterwards break intofrnall pieces for 
the convenience of carriage, expofing it to the air to dry* 
Although tincal has been colledled from this lake for a great 
length of time, the quantity is not perceptibly diminifhed ; 
and as the cavities made by digging it foon wear out or fill up, 
it is an opinion with the people, that the formation of frefii- 
tincal is going on. They have never yet met with it in dry 
ground or high fituations,but it is found in the (hallowed: depths, 
and the borders of the lake, which deepening gradually from, 
the edges towards the center contains too much water to 
admit of their fearching for the tincal conveniently ; but 
from the deeped: parts they bring up rock fait, which is not 
to be found in the (hallows, or near the bank. The waters of 
the lake rife and fall very little, being fupplied by a conflant 
and unvarying fource, neither augmented by the influx of any 
current, or diminifhed by any ftream running from it. The 
lake, I am affured, is at lead twenty miles in circumference, 
and (landing in a very bleak (ituation is frozen for a great 
part of the year. The people employed in collefling thefe 
falts are obliged to defer t from their labour fo early as October, 
on account of the ice. Tincal is ufed in Thibet for foidering 
and to promote the fufion of gold and filver. Rock fait is 
univerfally ufed for all domeftic purpofes in Thibet, Routan, 
and Naphauh 
The thermometer at Tiffoolumboo during the month of 
O&ober was, on an average, at eight o’clock in the morning 
38°, at noon 46°, and fix o’clock in the evening 42°. The 
Vol* LXXIX, O \ weather 
