Gold Mining Notes. 43 
sufficient amalgam has collected. When this is cleared 
out, the sand in the concentrator is slowly stirred for 
a quarter of an hour, to allow any mercury or amalgam 
to subside. The water and sand is then passed through 
a second and smaller concentrator after which it is 
allowed to run to waste. 
The amalgam when removed from the sluices is placed 
on a strong table on which is placed a large iron kettle 
into which the collected amalgam and quicksilver solution, 
amalgam one ounce to each flask of quicksilver, is put, 
and the whole stirred. Water is poured into the kettle, 
and the mixture stirred. The sand and mud which rise 
to the surface are removed with a large sponge, and this is 
repeated till the surface is clean. The whole is then 
stirred with the hands — the dirt which still comes to 
the surface being scraped off with a card, or bit of leather 
drawn over the surface. This is repeated with occasional 
stirring until the quicksilver seems clear. It is then 
poured into conical bags of canvas through the pores of 
which the mercury runs leaving the amalgam in the bag. 
The sodium amalgam should be prepared by the miner and 
used at once, since if long kept, it becomes oxidised and 
inactive and the coal oil in which it is kept is detrimental 
to the collection of gold. 
The sodium amalgam is easily prepared from metallic 
sodium, which can be kept in a wide mouthed bottle in large 
pieces covered with naphtha. A clean and dry frying pan 
is all that is necessary. Six pounds of clean mercury are 
poured into it and dried with a sponge, and then heated 
hotter than boiling water, but no more. A piece of sodium 
is wiped dry with a rag, and cut into small cubes ; and 
then the pan being placed in the open air with the 
F 2 
