Lead. 1»1 
at the bottom, which will also contain the silver and other 
metals if present. 
The triple sulphuret of lead, antimony, and copper 
found in Cornwall, was thus analyzed by Mr, Hatchett. 
Two hundred grains were put into a matrass with two 
ounces of muriatic acid, and heated, and nitric acid was 
added drop by drop, till the whole moderately effervesced* 
It was then gently heated for an hour, and a green solu- 
tion was formed, on which floated a quantity of sulphur, 
which was collected, digested separately with a little mu- 
riatic acid, and then washed and dried. It weighed 34 
grains, and afterwards burned away in a red hot earthen 
cup, without residue, and therefore was pure. The so- 
lution, with the muriatic acid in which the sulphur had 
been washed, was boiled, and then mixed with 6 pints 
of boiling distilled water, which it rendered instantly 
milky, and was filtered while hot, and the filter washed 
with more boiling water. The white precipitate left on 
the filter, when dried on a sand bath, weighed 63 grains, 
and was oxyd of antimony. The liquor with the wash- 
ings deposited on cooling some crystallized muriat of 
lead. It was evaporated nearly to dryness, and a few drops 
of sulphuric acid added to the liquor left, to separate in 
the form of a sulphat, what little of the lead remained in 
solution. The residue was then redissolved in boiling 
water, and decomposed entirely by sulphat of soda, and 
the sulphat of lead thus produced, (added to the former 
portion) was washed and dried on a sand bath, and weigh- 
ed 120.2 grains. 
The liquor which was now bluish- green, was rendered 
of a deep blue by ammonia, and a small quantity of oxyd 
of iron separated, which when dried and heated with wax, 
became magnetic, and weighed 2.4 grains. 
The liquor was then evaporated nearly to dryness, boil- 
ed with a strong lixivium of potash till nearly dry, and on 
