MERCURY. 
559 
for fifteen years in a low degree of heat, without its 
being in the least altered. We are told that the 
same philosopher had the patience to distill mer- 
cury more than five hundred times without any al- 
teration taking place. This metal unites very readily 
with gold and silver so as to form an amalgam. In 
Chili and Peru they turn the knowledge of this 
property to good account, and employ quicksilver 
to extract the native silver from its ores; after which 
the mercury is separated by heat in iron retorts, 
and the silver left in a state of purity. 
The amalgam of mercury and silver is susceptible 
of crystallization, and forms, with the addition of 
nitrous acid, a very curious apparent vegetation, 
known by the name of Arbor Diance. As the result 
of the process, when properly conducted, affords a 
pleasing and curious instance of mineral crystalli- 
zation, we shall describe the shortest way of effect- 
ing it. Dissolve four drams of silver and two drams 
of quicksilver in pure nitrous acid, aiid when the 
solution is completed add five ounces of distilled 
water. This must be put into a spherical vessel of 
white glass, containing six drams of an amalgam of 
silver, of the consistence of butter. The vessel must 
then be put in a perfectly quiet place, not subject to 
the least agitation, and at the end of some hours the 
figure of a brush or silver tree will be formed within 
the water of the glass vessel. The metals contained 
in the solution and in the amalgam attract each 
other, and a number of small four-sided crystals are 
