Loss of the Precious Metals
The Big Bonanza
by Dan DeQuille
of the Territorial Enterprise
The superintendent of a water-mill on the Carson River, when working for a considerable length of time an ore in which gold largely predominated, used every precaution to guard against loss. In addition to the usual settling-tanks, he caused to be dug in the ground a number of pits, into which the waste water flowed after leaving the tanks.
After leaving these pits, the water passed off in a small flume, and to the eye appeared as clear as the water of the purest mountain stream. For the sake of experiment, the superintendent coated a copper bowl with quicksilver and placed it in such a position that the water in the flume should fall into it. He also placed in the flume, below the bowl, some copper riffles, properly coated with quicksilver. Although the water passing through the flume appeared to be perfectly clear, yet at the end of three months the bowl and riffles were cleaned up and over a hundred dollars in amalgam was obtained.
This mill is driven by water taken from the Carson River and carried for a considerable distance through a large wooden flume. At one time it became necessary to shut off the water for the purpose of repairing this flume. In making the repairs it was found that in many places the heads of the nails driven into the bottom of the flume were thickly coated with amalgam. Within a distance of about three rods along the flume the workmen engaged in making repairs collected over an ounce of amalgam.
As further evidence that quicksilver in considerable quantities floats in the water of flumes and streams, below the reduction - works, in a state of invisible division and yet carries with it the precious metals, I may give an aditional instance. At a mill on the Carson River one of the workmen required a piece of copper. Remembering to have seen some old sheets of that metal lying near the waste - gate of the flume through which water was brought to the wheel of the mill, he went to the spot and hauled them out of a puddle in which whey were lying. Much to his surprise, he found the sheets heavily coated with amalgam and so eaten up by quicksilver that they were as thin as writing - paper. The water pouring out through the waste - gate had a fall of about fifteen feet. It did not fall directly upon the copper plates, but in a way as to keep them constantly splashed and wet. The plates had lain where they were found four of five years. Over a pound of amalgam was scraped off them. It would seem that in these striking instances of the unsuspected floating away of the precious metals there is for millmen food for reflection, and for inventers a field of profit and distinction.
Just what becomes of all the quicksilver used in the reduction - works of Nevada is a question that has never yet been fully and satisfactorily answered. Much floats away with the water flowing from the mills, but it cannot be that the whole of the immense quantities used is lost in that way. Quiksilver in great quanities is constantly being taken into the state, and not an ounce is ever returned. When it has been used in the amalgamation of a batch of ore, it is taken to the amalgamating - pans and is used over and over again until it has disappeared. Whether it may float away with the water used in amalgamating, or is lost by evaporation while in the hot - bath of the steam - heated pans, there must be a vast amount of the metal collecting somewhere, as it is a metal not easily deatroyed. In case it is destroyed by evaporation it must condense and fall to the ground somewhere near the works in which it is used, and if it floats away in the water it must eventually find a resting - place on the bottom of the stream in which it is carried away.
It is an axiom among millmen that "wherever quicksilver is lost, silver is lost " ; therefore there must be a large amount of silver lost, as we shall presently see. The amount of quicksilver used by mills working the Comstock ores alone averages 800 flasks, of 76 and one-half pounds each; or 61,200 pounds per month. This in one year would amount to 734,400 pounds of quicksilver that go somewhere, and counting backwards for ten years shows 7,344,000 pounds that have gone somewhere - either up the flue or down the flume.
The quantity of quicksilver distributed monthly among the mills shows just how much is lost per month. None is sold or sent out of the country in or with the bullion; therefore if there were no loss the mills would never want any more quicksilver than enough to give them their first start, as the same lot could be used over and over again ad infinitum.
Bridget E. Smith, editor & publisher
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Published in Portland, Oregon