36 B. 8. Burton—Contributions to Mineralogy. 
It is also in close accordance with Dr. Genth’s* analysis of the 
enargite from Brewer’s mine in South Carolina, The results 
demonstrate the mineral to be enargite, and this conclusion is 
fully sustained by its physical characters. 
Il. Argentiferous Jamesonite. 
In the metallurgical collection of the Sheffield Scientific 
School is an interesting suite of ores from the She ne, 8 
City, Nevada, and among these Prof, Brush found an argentif- 
erous sulph-antimonid of lead which he handed me for quanti- 
tative examination. The mineral is of a bluish white color, is 
massive to coarsely fibrous or columnar, ues is associated with 
quartz, zinc-blende and tetrahedrite. H.=2°5. Sp. Gr.=6-03. 
In the closed tube gives a sublimate of eight and sulphid 
of antimony. In the open tube affords sulphurous and anti- 
monial fumes. 3B.B. on charcoal gives copious fumes of sul- 
phur and antimony, with a coating of oxyds of antimony and 
lead, and yields a globule of lead, which on cupellation affords 
silver. A qualitative examination gave evidences of sulphur, 
antimony, lead, silver, copper and iron. 
In the quantitative analysis the mineral was decomposed by 
chlorine as described under enargite. The contents of the 
ere tube were removed and treated with dilute chlorhydric 
acid, brought upon a filter, washed with hot water, and the chlo- 
rid of lead thus dissolved was precipitated as sulphate, From 
the filtrate the copper was thrown down as sulphid by sulphy- 
ic acid gas. The residue containing the undecomposed min- 
eral with chlorid of silver was washed upon the filter with am- 
monia to dissolve the latter, and the silver was subsequently 
separated as chlorid by acidulating the solution with nitric 
acid. As the first determination of sulphur proved low, an 
conegiana absorbent was attached to the end of the tube filled 
cme g lass fragments i in the form of a nitrogen bulb apparatus, 
containing the mixture of chlorhydric and tartaric acids and a 
= te determination made; by this means the amount of 
phur was increased more than half a per cent, The anti 
eta was determined as in the enargite. The results of two 
analyses were as follows :— 
a ean, 
Sulphur, a 19°06 19°06 1°19 5 
Antimony, 29°08 29°45 29°26 "24 
Lead, 44 
"25 43°68 43°86 "424 
Silver, 615 613 614 56480 2 
Copper, 172 1°39 155 024 
Iron, 05 05 05 | 
: 99°76  100°02 
* This Journal, Hy, xxiii, p- 420. 
