322 Mr. Hatchett's Analysis of 
retort, I turned the bottom of it upwards, and poured some 
distilled water into the neck, so as to wash out the salt ; after 
this I increased the fire until the whole body of the retort was 
become red hot.* 
The residuum in the retort was a black blistered mass, upon 
which I poured three ounces of nitric acid diluted with an 
equal portion of water, and having distilled it, I repeated the 
operation, and thus converted the whole of the black matter 
into the yellow acid of molybdsena. 
When the retort was sufficiently cooled, I cut off the neck 
and removed the powder, which weighed 95 grains. 
I next proceeded to decompose the residuum left by the acid 
solution in the state of sulphate of lead, and having edulco- 
rated it, I boiled it during an hour with four ounces of lixi- 
vium of carbonate of soda, then washed the powder, and 
poured on it nitric acid much diluted. 
The whole was dissolved, excepting a small portion of white 
powder, which was washed and dried on a filter by the heat 
of boiling water, and then weighed seven-tenths of a grain. 
This, upon examination, proved to be siliceous earth. 
I then exactly saturated the nitric solution with lixivium of 
pure or caustic soda, and having washed and dried the preci- 
pitate of lead, I exposed it in a porcelain crucible for a quar- 
ter of an hour to an heat rather below red ; after which it 
weighed 146 grains. 
As I had found by a former experiment that a small portion 
of iron remained with the lead, I dissolved the 146 grains in 
diluted nitric acid, and precipitated the lead by sulphuric acid. 
* To be certain that all of the ammoniacal salt is decomposed, it is absolutely 
necessary that the retort should be made red hot. 
