W. F. Hillebrand—Léllingite and other Minerals. 385 
i RP en Soh aataen ey fog Me RI 42°97 
PE iki os Vea aS 8°43 
_ i RCE ecerte Vpn Be BM repent We eg 7°50 
| cd « MORI Mp paee Glen isan! Sash isin 22°49 
26 LO ie a ee ee 0°70 
V A COW ha manent Kec et iy Stic 9 trace 
eo er eee ee ee 
99:20 
Allowing for the iron and a proportionate amount of sulphur 
as pyrite, the atomic ratio deduced from the above is: 
Boo. ee cee 
2°07 x 1°00 eee 
showing the general formula for the mineral to be 2RS+Bi,S,, 
wherein R represents Pb and the double atoms Ag, and Cu,,. 
The ratio of Ag,+Cu, > Pb is 1: 1°11. ) 
~ Although copper was absent and but 2°65 per cent of silver 
present in the mineral originally described by Genth as cosalite, 
it does not appear advisable in the absence of any data as to 
the crystallographic form to consider this a distinct species, but 
to class it, as has been done with bjelkite, under cosalite. 
A PROBABLY NEW MINERAL. 
