ORES. 
3. The bismuthic silver ore was analysed by Kla 
proth nearly in the same manner. 
4. Carbonat of lead may be dissolved in nitric acid, 
collecting and estimating the carbonic acid. By boiling 
the solution, the iron and antimony (if any be present) 
will be separated, and may be estimated by solution in 
muriatic acid; precipitating the antimony by water, 
and the iron by ammonia. From the nitric solution 
the lead may be precipitated by sulphurie acid, and the 
carth may be examined by the rules laid down in the 
First Section of this Chapter. 
5. Phosphat of lead may be dissolved in boiling mu 
riatic acid. The solution is to be diluted with water till 
the crystals of muriat of lead are dissolved: being then 
saturated with ammonia, the léad and iron are precipi 
tated. Dissolve the precipitate in muriatic acid, eva 
porate to dryness, and treat the dry mass with alcohol. 
The muriat of iron is dissolved; but the muriat of 
lead remains. Finally, drop lime water into the am 
moniacal solution as long as any precipitate appeare. 
That precipitate indicates the proportion of phosphoric 
acid. 
6. Arseniat of lead has not been analysed. It might 
be treated with an alkali, which would separate the lead. 
This metallic precipitate is then to be redissolved in 
nitric acid, and analysed by the methods above described. 
The alkaline arseniat may be dissolved in water, and 
treated with nitrat of lead; 100 parts of the dry preci 
pitate indicate 33 of lead. 
7. Molybdat of lead was thus analysed by Mr Hatchet. 
The ore was boiled repeatedly with sulphuric acid till 
the acid refused to dissolve any more. The solution 
contained the malybdic acid. The undissolved powder 
155 
Chap. III. 
Laslhonnt. 
Nusee 
Arseniat. 
Mdee.