Assaying is the estimation of the amount of pure metal, and especially of the precious metals, in an ore or alloy. In the case of silver the assay is either by the dry or by the wet process. The dry process is called eupellation from the use of a small and very porous cup, called a cupel, which is usually made of well-burned and finely-ground bone-ash or of magnesia. The cupel, being thoroughly dried, is placed in a fire-clay oven about the size of a drain-tile, with a flat sole and arched roof, and with slits at the sides to admit air. This oven, called a muffle, is set in a furnace, and when it is at a red heat the assay, consisting of a small weighed portion of the alloy wrapped in sheet-lead, is laid upon the cupel. The heat causes the lead to volatilize or combine with the other metals, and to sink with them into the cupel, leaving a bright globule of pure metallic silver, which gives the amount of silver in the alloy operated on. In the wet process the alloy is dissolved in nitric acid, and to the solution are added measured quantities of a solution of common salt of known strength, which precipitates chloride of silver. The operation is concluded when no further precipitate is obtained on the addition of the salt solution, and the quantity of silver is calculated from the amount of salt solution used.
An alloy of gold is first cupelled with lead as above, with the addition of three parts of silver for every one of gold. After the cupellation is finished the alloy of gold and silver is beaten and rolled out into a thin plate, which is curled up by the fingers into a little spiral or cornet. This is put into a flask with nitric acid, which dissolves away the silver and leaves the cornet dark and brittle. After washing with water the cornet is boiled with stronger nitric acid to remove the last traces of silver, well washed, and then allowed to drop into a small crucible, in which it is heated, and then it is weighed. The assay of gold, therefore, consists of two parts: cupellation, by which inferior metals (except silver) are removed; and quartation, by which the added silver and any silver originally present are got rid of. The quantity of silver added has to be regulated to about three times that of the gold. If it be more the cornet breaks up, if it be less the gold protects small quantities of the silver from the action of the acid. Where, as in some gold manufactured articles, these methods of assay cannot be applied, a streak is drawn With the article upon a touchstone consisting of coarse-grained Lydian quartz saturated with bituminous matter, or of black basalt. The practised assayer will detect approximately the richness of the gold from the colour of the streak, which may be further subjected to an acid test. The Goldsmith's Company of London is the statutory assay-master of all England. Research Assaying
Bonanza, from the Spanish meaning 'fair weather' or 'a favouring wind', was a term first applied in the United States to an abundance of precious metal or rich ore in a mine. The term became applied to a run of good luck or great prosperity generally. Research Bonanza
A stamp mill is a machine used for the fine crushing of mineral ore. The stamp mill consists of a cast iron rectangular box provided with a feed slot at the back and screens in the front. A number of stamps consisting of heavy stems with a steelshoe at the bottom work in each box. The stamps are raised by means of cams and falling by gravity crush the ore on the steel dies placed in the bottom of the box. Water flowing through the boxes carries the crushed ore through the screens. Research Stamp Mill
In mining, stope is excavation for the extraction of ore stepwise, or like a staircase. In overhand stoping, the staircase is inverted, and the ore is found in the roof of the stope; in underhand stoping the ore is found at the bottom. Stoping has the advantage that such excavations require comparatively little shoring. Research Stope
In mining terminology, tailing (also known as the tails) is the refuse part of stamped ore, which is thrown behind the tail of the buddle or washing apparatus. It is dressed over again to secure whatever metal may exist in it. Research Tailing
Brigham Young was an American Mormon leader. He was born in 1801 at Vermont and died in 1877. A mechanic in New York, he was converted to Mormonism in 1831, and became an intimate associate of Joseph Smith. Commencing to preach the next year, he soon removed to Kirtland, Ohio, was chosen elder in 1832 and apostle in 1835. Brigham Young was ore of the founders of the Nauvoo settlement in 1840, and in 1844 he succeeded Joseph Smith. Owing to persecution he conducted an emigration in 1846, and passed the following winter among the Indians of Nebraska. Having in 1847 explored the Salt Lake valley, he returned and led his band to the new home in 1848. He became Governor of Deseret in 1849, and was appointed Governor of the Territory of Utah in 1851. The next year he announced the dogma of polygamy, and systematically defied the National Government He submitted, however, to Johnston's expedition of 1857. He remained president of the Mormon Church until his death. Research Brigham Young
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Abbreviations
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