420 
The Extraction of Gold. 
[July, 
„ n A metallurgical expert, came over to London about a yeai 
a"o to consfit with P th’e leading British and Contmenta 
metallurgists and to devise, if possible, some moie excellent 
wav. After many, and we may say costly experiments, they 
came upon a totally new process, which in the opinion o 
the best judges, and, what is more, in acftual trials °n the 
large scale, bids very fair to get over the difficulties which 
we have above enumerated. • . 
The inventors propose, in the first place, to comminu 
the ore not in a wet state, but perfectly dry The Pulve- 
rising process is effetted not by means of a battery of 
stampers but by means of a “Jordan pulverisei.. This 
apparatus afts not by grinding or stampmg, but by impadt 
or concussion, soraethtng -after the manner of a Can s dis 
integrator. The stone is reduced to a powder as fine as 
flour so that it passses through a sieve of 8100 meshes to 
the square inch, or, in round numbers, forty times as fine as 
is done in the old process. Hence all the loss dependent on 
the circumstance that much gold remains still locked up 
within the grains or fragments of quartz or pyrites is got 
rid of. . The use of water is dispensed with entirely, and 
though the pulverising is so much more perfedt it is effected 
at an average cost of 8s. per ton, as against 16s. 6d per ton 
by the stamping process, so that here already there is a 
saving of 8s. 6 d. per ton. • 
We come next to the amalgamation. The mercury is 
applied dry and hot. The ore, reduced as above to an im- 
oalnable powder, is passed upwards through a column of 
heated mercury 30 inches in height, and during this passage 
Us kept constantly distributed through the mercury by an 
ingenious self-adting apparatus. The details of this part of 
the process can not be intelligibly described without the use 
of nlates or, better still, of a working model. We can 
merely say that the ground ore is fed into a hopper at the 
top of a revolving tube. Passing down this it is centnfu- 
o-allv forced into the mercury, and would then, in conse- 
quence of its lower specific gravity, at once rise to the 
surface. To prevent this too rapid escape it is constantly 
agitated in the mercury by a set of revolving blades. 1 hese 
c?n be adjusted in their number, in their speed of rotation, 
and in the angle at which they are set, so that the pulverised 
ore can be kept in contaft with the heated mercury foi a 
longer or a shorter time, according to the qua hty of the 
stone which is being operated on. A steam jacket outside 
the pan maintains the mercury at the temperatuie desued. 
When, finally, the ground ore reaches the top of the column 
