the Carinthian Molybdate of Lead. 309 
was then edulcorated, and the acid solutions being added to- 
gether, formed a pale blue transparent liquid. 
To decompose the white residuum, I boiled it during an 
hour with lixivium of carbonate of soda, then washed the 
powder, and poured on it nitric acid much diluted, by which 
it was immediately dissolved with effervescence, leaving a very 
small residuum of siliceous earth. 
Prussiate of pot-ash produced a white precipitate of lead, 
and after 12 hours, a very small portion of Prussian blue sub- 
sided. 
The ore was therefore decomposed, and there only re- 
mained this minute portion of iron to be separated from the 
lead ; but this I shall notice when I come to the analysis. 
I now diluted the sulphuric solution with a large quantity 
of distilled water, and divided it into two portions. 
One of these (which I shall call A) was saturated with car- 
bonate of pot-ash. The other (B) was saturated with carbo- 
nate of ammoniac. 
When the alkalies were first added, the solutions became of 
a pale yellowish green, and as the quantity of the alkalies was 
increased, the solutions changed to bluish' green, and lastly to 
deep blue. 
When the vessels had stood about 24 hours, the solution A 
deposited a white precipitate, and in the solution B there was 
also a small quantity of a yellowish colour. 
Both solutions passed the filter without any diminution of 
the blue colour. 
I collected the white precipitate of A on a filter, and then 
evaporated the liquor to half. 
The following morning I found a large quantity of crystal- 
