9£ M. Brongniart on the Fresh-water Formations of Italy. 
The white copper is used by the Chinese themselves, who are 
so jealous of permitting other nations to have it, that its expor- 
tation is contraband. In defiance of this, however, considerable 
quantities of it are smuggled out of the country, and introduced 
into India, where it is considered as a great present to the Hin- 
doos, &c. who make domestic vessels of it. The Tutenag, on 
the contrary, is an article of very extensive commerce between 
China and India ; and my friend informs me, that it is sent 
from China in slabs, of which he has had occasion to buy and 
sell many thousands. The slabs are about eight or nine inches 
long, by about five and a half wide, and about five-eighths thick. 
Its colour is greyish ; and it is not malleable, but so brittle that 
it is even necessary to use considerable caution in putting it on 
ship-board, to prevent its being broken by one piece striking 
against another. The fracture has a glittering lustre, and some- 
what resembles the appearance exhibited by that of bad iron ; 
but the crystallization (if such a term may be employed) is 
, larger. It does not ring, but emits a heavy clattering sound. 
It is employed by the natives of India as an alloy for copper, to 
make brass for their domestic utensils. 
I consider it right to send you the above information, as I 
think it may perhaps be interesting to your readers. I remain, 
my Dear Sir, yours faithfully, 
Belugas, ) Thos. D. Lauder, 
llth July 1822. j 
Art. XVII . — On the Fresh-water Formations of Italy , poste- 
rior to the Coarse Limestone. By Alexander Brong- 
niart, Member of the Institute of France, &c. &c. 
M • Omalius dTIalloy, was the first geologist who referred 
to the fresh- water formations, the calcareous rocks, so well 
known in the neighbourhood of Rome and of Sienna, under the 
name of Travertino ; and who showed, that, with the exception 
of fresh- water shells, which he could not discover in the traver- 
tines of Tivoli, this limestone presents otherwise all the charac- 
ters of texture in the small, and of position and relation in the 
great, which belong peculiarly to the lacustrine formations, such 
