doant de Bournon's Description , See. 31 
or one of those compound metallic bodies in which various 
metals are combined with the same mineralizing substance, as is 
frequently observed in mineralogy. At length Mr. Hatchett, 
to whom the science of mineralogy is already under many 
obligations, has added to them, that of having determined, in the 
most satisfactory manner, the place this substance ought to oc- 
cupy amongst metallic bodies. Mr. Hatchett has ascertained, 
that it is a triple sulphuret, in which the sulphur is combined, 
at the same time, with lead, antimony, and copper. Mineralogy 
has hitherto furnished very few instances of triple metallic sul- 
phurets, particularly of such as (like that here described) 
exhibit their characters in as striking a manner to the mineralo- 
gist as to the chemist. 
The colour of this mineral is a dark gray, inclining to black. 
It has a very brilliant lustre. 
It is very brittle ; fragments of it may be easily broken off 
by means of the nail. 
Its hardness is such, that it very easily cuts calcareous spar; 
but it is not sufficiently hard to scratch fluor spar. 
When rubbed pretty strongly on white paper, it leaves on it 
a faint black mark ; but not so readily as lead, or sulphuret of 
antimony. 
It does not, when rubbed, emit any smell. 
When grossly powdered, the powder still retains the metallic 
lustre. 
When thrown, in the last mentioned state, upon an iron not 
quite red hot, it emits a phosphorescent light, of a bluish-white 
colour, but without any smell whatever ; no such light, however, 
can be obtained from it by means of friction. 
