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the gold amalgamated while in a perfectly dry condition. In the second, the ore is 
reduced entirely by impact, and not by abrasion, so that the particles are not rubbed 
or pounded together. Complete separation and individuality of the various constituent 
particles is thus maintained, the ore being divided into a powder of extreme fineness. 
In the third place, in this finely-divided, clean, and dry condition the ore is subjected 
to the action of mercury under considerable pressure, and under the constant action 
of mechanism, which continually separates the particles. The ore is thus retained 
under the mercury a sufficiently long time for each particle of the gold-bearing powder 
to be effectually acted upon by the mercury. Fourthly, the whole process is perfectly 
automatic from first to last, air currents being employed for the separation, conveyance, 
and delivery of the ore powder instead of sieves, water, and labour.” Iron adds, that 
“ the process is an exceedingly simple one, and that the principles embodied in the 
system of treatment meet the difficulties which have hitherto prevented successful 
operation on pyritic and arsenical auriferous ores, which form such a large proportion 
of the gold-bearing minerals.” 
Otto's Electric Gold-saving Apparatus .— In August last, the Senior Inspector of 
Mines (Mr. Nicholas) furnished me with the following report respecting this 
invention: — 
In compliance with your instructions, I have inquired into the experimental tests of the merits of 
Mr. Otto’s gold-saving electric apparatus, made at the Welshman’s Reef, Sandy Creek, and at Messrs. Rowe 
Brothers’ mine, Fryer’s Creek. 
The manager of the A\ elshman’s Reef mine (Mr. John Opie) informed me that the particulars of the 
trials reported in the Mount Alexander Mail, of the 30th May last, were perfectly correct. He overlooked 
the crushing of the ton ot refuse left by the last miuers who worked the claim, also of a toil of quartz from 
the Mia Mia, and of half-a-ton of tailings from the old battery. He also attended to the retorting of the 
quicksilver, and saw a very satisfactory yield of gold as the result of each test. I examined the refuse heap 
still lying beside the shaft, also the tailings from the old battery, and noted that they were free from 
pyrites or any other sulphurets. 
Mr. E. W. II. Rowe, the senior partner of Messrs. Rowe Bros J firm, was present at the trials of 
Otto’s gold-saving electric apparatus, at the battery of their Duke of Cornwall mine, Fryer’s Creek. He 
stated that the report which appeared in the Argus of the 14th June was furnished by themselves, and 
was a plain statement of the facts. 
The trials at this mine -were with the ordinary quartz, with raw and roasted pyrites, and with 
tailings from the old battery. The experiments on the pyrites, whether raw or roasted, do not appear to 
have been attended with any markedly favorable results ; but those made on the ordinary quartz, after 
passing through and over the usual gold-saving appliances, and on the tailings from the old battery, must 
be regarded with interest by all mine-owners. The first indicates an increased yield of gold from ordinary 
quartz amounting to 20 per cent., and the second that the immense accumulations of quartz tailings on the 
gold-fields may again be 'worked over with profit. In concluding my report on this new gold-saving 
process, I must record a not unimportant point noted by me, viz., that the experiments were made with 
an electric apparatus of insufficient capacity. 
The following are the reports referred to by Mr. Nicholas, which appeared in the Mount 
Alexander Mail and the Melbourne Argus:—Mount Alexander Mail , 30th May, 1884.—“ Mr. C. M. 
Otto, a mechanical electrician, employed at the Melbourne Observatory, is the inventor and patentoc 
of this instrument or apparatus. A practical model has been made, about equal in capacity to the 
crushing-power of three stampers working at half speed, so that an apparatus large enough to pass 
through the ■whole of the crushed quartz from a fivo-liead battery would have to he three times as large as 
the model, which is less than a foot iu width and two feet in length. It is made of iron, and is simplicity 
itself. There is nothing to got out of order or break under all ordinary circumstances, and the whole 
mystery, if there is any, is the creation and application of the electric current by which all free gold is 
to he extracted out of quartz tailings and other, gold-hearing material. The zinc-connexion from the 
electric battery is in direct connexion with the mercury, and insulated from the carbon poles, which 
are fixed opposite each other, right across the mercury, and a little above it. These sheets or slabs of 
carbou can he adjusted at pleasure to regulate the strength of the electric current, and are connected with 
the carbon from the electric battery. These carbon poles placed above the mercury produce the following 
effects:— Water being a good conductor of electricity, as it comes out of the stamp boxes and passes 
through the instrument and over the mercury, completes the electric circuit, and makes the whole surface 
and body of the mercury galvanic. As a consequence, the mercury is always bright, and attracts the gold, 
taking it out of the crushed material, much the same as a magnet would iron-filings, as it passes between 
the mercury surface and the carbon poles. 
“The operations carried on were under the supervision of Mr. Otto, the mining manager of the 
Welshman’s Company, and the chairman of the Board. A number of miners and gentlemen were there to 
watch the experiment, which was open to anybody in every stage of its progress. The first stuff dealt with 
was a ton of mullock from which the colour of gold could be obtained by dish washing; the second was 
quartz and bed-rock from a reef in the neighbourhood, quantity about a ton ; and the third, half-a-ton of 
tailings that have been on the ground for many years. In every respect the experiments were completely 
successful, saving flour gold, and leaving not a trace of gold or silver in the material passed through. 
“ Some of the advantages claimed for this machine are that it does away with every necessity or 
excuse for using mercury in the stamp boxes or in the ripples, and thus causes a saving of mercury. It is 
affirmed that, without doubt, it takes or captures all the free gold. It is also asserted that the electric 
current dissolves the gold and that it will act upon auriferous pyrites without sickening the mercury, and 
take the gold out of that most difficult and costly material to deal with; hut of this we at present have no 
