GoopanL.—Notes on Quartz Crushing at the Thames Gold.fields. 211 
The quicksilver and amalgam in the boxes, being continually battered, 
passes away as floured quicksilver, even floating on the water, the heavier 
particles rolling off the plates. This is amply proved by the great 
loss of quicksilver that is experienced constantly, and by the quantity 
that has been washed out of waste tailings. What remains in the 
battery is sickened, and is unfit for amalgamation, and thus allows the 
gold to escape. The reduced material then passes over the quicksilver 
plates, and then over blanket strakes, which are often washed. The blanket 
tailings are then amalgamated in large berdans, having a loose and a 
drag ball. In this process gold and quicksilver are not only lost, but a 
great deal of power is wasted, thereby increasing the cost of the produce of 
gold. It is difficult to reduce any material to a fine state by stamping— 
beyond a certain amount: in quartz, we may presume, to less than one- 
sixteenth of an inch in diameter; down to that it is comparatively easy, by 
the use of coarser gratings than those now used. It would be an easy 
matter to grind the coarse tailings by a separate grinding machine. I 
would further recommend the use of wire gratings, instead of punched 
sheets. Wire gratings, although not so strong as the other, will admit of a 
better flood, and the extra trouble of replacement would be well compen- 
sated for by the extra amount of work done. Another great fault is the 
amalgamating in the berdans, where great loss is experienced in gold, 
quicksilver, and power. The drag grinds the berdan more than the tailings, 
and converts a part of the quicksilver and amalgam into floured particles 
that readily pass away. 
Having described what, in my opinion, are the defects of the present 
system, I would recommend the following treatment to utilize the present 
appliances, with some small alterations and a few additions. Crush the 
quartz (after it has been puddled to get rid of the clay that exists in 
mullocky leaders), coarsely, without quicksilver, in the battery, using wire 
gratings, having, say, 81 holes to a square inch. Save as much gold as 
possible by the quicksilver plates and ripples. The tailings should then be 
gathered in pits, and passed through grinding machines, or passed direct 
from the silver plates through the grinding machines. When the tailings 
are fine enough, they should be amalgamated in barrels, or any other 
gentle system of amalgamation. One berdan should be sufficient for a large 
establishment, and it should be reserved for the cleaning of amalgam only. 
The whole of this could be easily arranged, and it would cause less work 
than is now entailed in working a battery, and I am confident a great deal 
less power will be necessary, and more gold saved. 
LI 
