On the Purifwation of Mercury. 35% 
perhaps somewhat contributed, from its being so little curved 
that some particles might escape in the ebullition into the re- 
ceiver. Not wishing to undertake a new distillation, I placed it 
in six vessels, aud covered the mercury in each about the depth of 
an inch with diluted sulphurie acid. After five days of repeated 
and frequent agitation, having washed, dried, and passed it through 
paper, I found that it left no black stain on a delit plate, that its 
drops had ne appendage or tail, and that it evinced a most bril- 
liant surface, which did not tarnish during the space of several 
days that I kept it before applying it to use. 
But whoever wishes by this process to purify mereury much 
amalgamated, should use sulphuric acid not diluted, in order to 
hasten the operation. In fact, having exposed mercury which 
had been used for what is called the revival of sheet-lead, and 
for the preparation of plain mirrors, to the action of this acid, in 
the space of some days it became equal in goodness to that which 
had undergone the preceding operation. The facts, however, 
which I have described, demonstrate that the above process is 
sufficiently useful in purifying mercury adulterated by other me- 
tals; and to confirm it, I was induced in May 1815 to resort to 
the following new experiments. 
First. 1 made by means of heat four amalgams of the following’ 
compounds. 1. Two denari* of lead and two of bismuth with 
two ounces of mercury, 2. Four denari of lead with two ounces 
of mereury. 3. Four denari of tin with two ounces of mercury. 
4. Two denari of lead and two of tin with two ounces of mer- 
cury. I then added to each of these six ounces of mercury. 
Secondly. I put these amalgams, which had a dense and 
wrinkled pellicle ou their surface, in so many bottles numbered 
with their respective numbers, and added concentrated sulphuric 
acid sufficient to cover each amalgam to the depth of two or 
three lines of a quarter of an inch. Afterwards by repeated 
agitation and changing the acid several times, I obtained in a 
greater or less number of days mereury, which I have, and which 
retained, after being kept many days, the most beautiful bright- 
ness. The amalgam No.2 was the first to yield pure mercury, 
the last was No. 1. : 
In this and in ether experiments where I used concentrated 
sulphuric acid, I observed almost instantly around the amalgam 
a whitish, yellowish, or grayish powder, which always increased, 
and which I separated at the first washing, by putting into the 
bottle a new quantity of acid. With agitation the mercury di- 
vides into larger or smaller globules ; not immediately, nor in @ 
given time, but usually when it is somewhat purified. In the 
proceas more or less sulphurous acid is disengaged, and also sul- 
* A denaro is the twenty-fourth part of an ounce. 
phuretted 
