43 
added the ilvait (the yenite or jenite of some saloon. 
mineralogists), which is now enumerated by Nat. Hist. 
Haiiy among the ores of iron, under the appel¬ 
lation of fer siliceo-calcaire. 
(Case 41.) In this and the two following cases 
are contained the ores of lead, the most common 
and useful of which is the sulphuret of lead, or ga¬ 
lena : the specimens here deposited include vari¬ 
ous modifications of crystals, detached, and 
grouped together, in combination with blende, 
pyrites, and many other substances; galena of 
various grain, massive and disseminated; galena 
of corroded appearance, decomposed and re¬ 
generated ; the compact and specular variety, 
called slickenside by the Derbyshire miners.-— 
With these is also placed the antimonial sulphu¬ 
ret of lead , or triple sulphuret of lead, antimony, 
and copper, called endellion by Count Bournon. 
[See British Collection : Cornwall.] 
(Case 42.) Ores of lead continued :—the more 
prominent specimens in this case are those of car¬ 
bonate of lead, or white lead, among which may 
be particularized the laminar varieties, the beau¬ 
tiful modifications from Siberia, and the crystal¬ 
lized acicular white lead from the Hartz, accom¬ 
panied with green and blue carbonates of copper ; 
the fine light-blue variety coloured by copper, 
&c.; the black lead ore of Werner, which appears 
to be merely a variety of the white lead ore.— 
With these are placed three substances from 
Leadhills, hitherto considered as carbonates, but 
which, according to analyses lately published. 
are 
