mo 
A brief Account of the 
hand, and jerks it with considerable force down towards 
a wooden trough (a receptacle for the quicksilver) till, 
by repeated jerks, all the loose particles of mercury are 
disengaged, leaving a complete continuity over the sur- 
face, and giving them the appearance of silver buttons. 
Now the gold, a grain of which will spread over ma- 
ny superficial feet of copper, is thus prepared : Any 
given quantity of mercury is poured into an iron ladle, 
the inside of which having been previously guarded,— 
that is, rubbed over with dry whiting to prevent the gold 
from adhering to the iron,— into this mercury is thrown 
the portion of pure gold intended to cover a given quan- 
tity of buttons. The gold and mercury are heated to- 
gether in the iron ladle till the workman (whose practice 
soon enables him to judge) perceives that there is a per- 
fect union between them ; when he empties his ladle into 
a vessel containing cold water. 
The amalgam being cold, is put into a piece of sham- 
moy leather, and squeezed till no more mercury will pass 
through. What passes the shammoy contains not the 
smallest portion of gold ; what remains will be about the 
consistency of butter, so completely united that every 
particle of mercury shall contain an equal portion of 
gold. The amalgam should be then put into an earthen 
vessel, and a small quantity of nitric acid added thereto, 
allowing sufficient time for the acid to unite with the mer- 
cury. But the buttons and amalgam are commonly intro- 
duced first, and a quantity of diluted nitric acid added 
thereto, so that, for want of a complete union between the 
mercury and acid first, if there be not a superabundance 
of acid, there may not be sufficient to carry all the amal- 
am to the surface of the buttons* 
When the acid has had sufficient time to embrace (as 
workmen call it) the mercury, the buttons should be in- 
troduced, and be stirred till the amalgam, carried by the 
