Mr. Hatchett's Analysis of 
*94 
§IV. 
As Mr. Klaproth had proved the action of the fixed al- 
kalies on the molybdate of lead, in the dry way, I was de- 
sirous to know what effects they would produce in the humid 
way, and therefore made the following experiments. 
EXPERIMENT I. 
A. I boiled four ounces of strong lixivium of caustic pot- 
ash with twenty grains of the purified ore, till there remained 
at the bottom of the matrass a dry mass, which was partly 
red, yellow, and green. I reduced this to powder, and poured 
distilled water on it, till the water came away without any 
taste. 
The alkaline solution was filtrated, and afterwards satu- 
rated with sulphuric acid. The liquor then became turbid, and 
deposited a small quantity of a white precipitate, which con- 
sisted of lead and some molybdic acid. This was separated 
by a filter, and prussiate of pot-ash being added to the clear 
liquor, precipitated a great quantity of molybdasna, in the 
state of a reddish-brown flocculent precipitate. 
B. I took the residuum of the alkaline solution (which 
now was chiefly of a red colour, and appeared like minium) 
and poured nitric acid, very largely diluted, on it till the whole 
was dissolved. I then precipitated the lead with sulphuric 
acid, and from the clear liquor which remained I afterwards, 
by the means of prussiate of pot-ash, obtained a quantity of 
Prussian blue. 
