50 A NEW TEST FOR MERCURY. 
teristic growths of Al, 03 will be seen if mercury is present. 
1-500th of a grain of mercury may be detected in viscera, 
etc., by this method. The advantage this method has, 
is that small quantities of impurities such as fatty matters 
do not interfere. 
To detect small quantities of mercury in an ore.—Take 
from 0.5 to 1 grm. of the thoroughly sampled and finely 
ground ore and mix with about an equal bulk of lime and 
a little reduced iron (or other reducing agent), and place 
it in a small combustion tube placing a strip of aluminium, 
previously cleansed, over the mouth, and heat the mixture 
to dull redness, keeping the aluminium cool with a few drops 
of water. Then rub the aluminium with a wash leather 
moistened with a caustic alkah solution. If mercury, is 
present in the ore, there will be the characteristic growth 
of alumina. 
