14 



dexterously impelled at times rotatory, at times in such a manner, that the 

 motion becomes a combination of that of the shaking-table with that of the 

 jigger. From the above described process, which is principally applied to cop- 

 per, lead, silver, eventually also to iron-ores and ores of antimony, the treat- 

 ment of gold-ores somewhat differs. 



WASHING OF GOLD-OEE8. 



These are in the first place pounded in the usual way, and then ground on 

 hand-mills with the aid of water. The pulp, that flows out from the mill, is 

 carried over inclined scarred boards into launders. In the furrows of the boards 

 (" Neko " i. e. literally : cat), which correspond with the Californians' blankets 

 and the ox-hides of the South-Americans, the heavier particles of the washings 

 remain as sediment. They are removed by washing or knocking. The con- 

 centrations, thus procured, are then farther concentrated either on the above 

 mentioned flat boards, or in laquered dishes, similar to the soup-bowls of the 

 Japanese table-service — , until finally gold-sand is obtained. This is then 

 melted with borax in clay-crucibles, and by the worker handed to the adminis- 

 tration of the mine against a certain remuneration — usually yen 2 per momme 

 (1 momme = 3,7 5 grammes). The sands and slimes from the launders are 

 occasionally again returned to the mills, and repeatedly subjected to a similar 

 process. Nay, when ore is scarce, the tailings, which have been accumulated 

 through centuries, are again worked over. As this renewed manipulation re- 

 quires no mining expenses, it follows that it needs only a small percentage of 

 gold to make the operation yield a profit, although it be a rather modest one ; — 

 the limit is about 3 / s ounce = $7 % per ton. 



The winning and washing of gold-ores is very often carried on by each indi- 

 vidual miner's family separately ; then the men procure the ore, the children do 

 the transport from the pitches to the mills, the women and girls the pounding 

 and washing of the ores. Under this arrangement, it is necessary, that each 

 family is possessor of its own mills and launders. 



IMPEOVEMENT IN DEESSING. 



The result of the dressing, however primitive the latter, can, generally speak- 

 ing, not be pronounced bad; nay, the product is perhaps often purer than 

 can be obtained by the aid of machinery, and the skill of the gold-washers 

 is so great, that the worth of only $1 — x / 20 ounce per ton, although of course 

 it cannot be profitably extracted, can be detected even in pyritic ores. 



But it requires no further demonstration, that the dressing — from first to last 



