1876.] 
437 
Japanese Mines. 
copper lifted out, in more or less circular cakes, by throwing 
water on its surface and raising the solidified crust with an 
iron tool. This process has many advantages for a country 
like Japan, where the means of intercommunication are so 
bad, and coal is, therefore, not available as fuel. 
Japan possesses both gold and silver, although not in very 
large quantities. Mr. Plunkett gives no account of these 
mines in his Report ; in fa6t he does not believe that they 
are at present of much value. As the Japanese Government 
has recently turned its attention to their development, and as 
considerable interest attaches to the subject, we will condense 
into as brief a space as possible — from the columns of the 
“ Hiogo News,” an English newspaper published in Japan — 
an account of the silver mines of Ikouno, in Tajima. On the 
hill-side, above the works, are to be seen a number of places 
like large rabbit-holes, and a tramway which runs round the 
face of the hill, connecting the holes with a series of shoots, 
by means of which the ore is passed down to the works. 
Entering one of the holes referred to, which prove to be the 
mouths of galleries, we see the first process of removing the 
ore by blasting, the fuses for which are now all made on the 
premises. Emerging, we find the ore at the deliveries of 
the shoots being broken with hammers into pieces, varying 
in sizes, the richest portions being broken the smallest. The 
poorer lumps, and those which contain a preponderance of 
other minerals, are set aside for consumption at convenience. 
The more choice morsels are set out, according to quality, in 
five classes of an estimated value, on appearance of bearing 
silver in the proportion of from 80 dollars per ton to 5000 and 
upwards. These fragments are then pounded into dust in 
crushing-mills, and the dust baked in ovens with common 
salt. Hitherto the silver has been combined with sulphur, 
but in these ovens a chemical change takes place, the chlorine 
of the common salt combining with the silver (and the 10 to 
12 per cent of gold which the ore contains), and the sulphur 
combining with the sodium of the salt to make Glauber’s salt, 
which is sent into the river. The ore— -now a red earth — is 
next, by means of water and iron balls, thoroughly mixed with 
a large quantity of quicksilver, by the aid of revolving drums. 
Under this process the quicksilver takes up the precious metal, 
and when the amalgamation is complete the drums are 
emptied, and the now comparatively valueless mud washed 
away. The combined, and still fluid, metals are then treated 
with hydraulic pressure against a leather sieve, through which 
free mercury is extruded, leaving a putty-like, brilliant, white 
amalgam. Heated in iron retorts, the remaining mercury 
