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 COPPERMINE —COPTIC These are usually suspended in slate vats, owing to the higher voltage used. In the multiple system the anodes .are generally cast plates of from 1 inch to II inches in thickness, while in the series system they must be rolled sheets, usually | inch thick. The multiple system anodes .are sometimes cast directly from the blister furnace or the converter, but they are smoother, more compact, and make less scrap if roughly refined. At the Anaconda works the Bessemer copper is poured into a revolving cylindrical refinery, where it is poled, and thence poured into large ladles mechanically handled, which hold the measured weight of an anode. At other works similar ladles capable of holding 150 lb are moved by overhead trolleys. At the Baltimore works Walker’s travelling tables present the moulds in rotation to the pouring ladle. The old method of slow hand-ladling has been discarded in the United States works, and the refining furnace, whether for making anodes or casting the cathodes, has been enlarged to a capacity of from 80,000 lb to 120,000 It) to a charge. The electrolyte is invariably an acidulated solution of cupric sulphate. The ■current density seldom if ever exceeds 18 ampbres to the square foot, and it can be economically raised to that point only when a high temperature and rapid circulation of the electrolyte is maintained. In some rare instances where water power is in excess of requirements, the ■electrolyte is heated by raising the resistance and by forcing the current through small conductors. With an 18-ampere current, anodes of 1 inch thickness are dissolved in 15 days, and therefore a plant of given size to-day, using a current of high density, turns out at least three times more copper than formerly, when a current density of 6 amperes per square foot was deemed the highest safe maximum limit. The accumulation of dangerous quantities of impurities in the electrolyte is corrected in most works by withdrawing at intervals a given proportion of the whole, recovering its valuable contents and replacing it by pure electrolyte. The metals which it is the aim of most works to recover from copper anodes are •copper, gold, and silver. The former is deposited on the cathode, while the precious metals separate and collect as .slime, with their valuable or valueless ingredients, in the bottom of the vat, or as a coating on the anodes. Copper is invariably used as the conductor, and almost every works adopts different methods of attaching the electrodes to the permanent conductors. The only published statement of the cost of refining copper on a large scale is that given in the report of the Anaconda Company, which turns out from its works in Anaconda about 80,000,000 lb of copper annually. The total cost, including taxes but not interest on plant, was in 1897-98, ■§ cent per pound. This is in excess of the cost on the Atlantic seaboard and in Europe, where fuel and labour are both cheaper. Only electrolytic copper, together with that from Lake Superior, has sufficient purity and conductivity to be used for electrical purposes. It enters the market as cathodes, which are the rough plates, as withdrawn from the tanks, or ■cast into ingots, wire bars, and cakes. The conductivity of the cathodes is higher than that of the copper cast from them. Copper can be electrolytically deposited on irregular moulds, ■or as tubes on revolving mandrils. To ensure density, where this is done, agate burnishers travel over the surface ■of the tube during deposition, as in the Elmore process. Modern methods in copper smelting have therefore effected enormous economy in time, space, and labour. To-day with pyritic smelting a sulphuretted copper ore, fed into a cupola in the morning, can be passed directly to the converter, blown up to metal, and shipped as 99 per cent, bars by evening—an operation which formerly, with heap roasting of the ore and repeated roasting of the

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mattes in stalls, would have occupied not less than four months. A large furnace and a Bessemer converter, the pair capable of making a million pounds of copper a month from a low-grade sulphuretted ore, will not occupy a space of more than 25 feet by 100 feet; and whereas, in making metallic copper out of a low-grade sulphuretted ore, one day’s labour used to be expended on every ton of ore treated, to-day one day’s labour will carry at least four tons of ore through the different mechanical and metallurgical processes necessary to reduce them to metal. (j. Ds.) Coppermine, a river of Mackenzie district, Canada, about 475 miles long, taking its rise in a lake in approximately 110° 20' W. long, and 65° 50' N. lat., and flowing south and then north - westward to Coronation Gulf in the Arctic Ocean. It was discovered by Hearne in 1771, and was explored from Point Lake to the sea by Captain (afterwards Sir John) Franklin in 1821. Coptic Church.—Racially the Copts are descendants of the ancient Egyptians, the name Egypt meaning “land of the Gypt,” as the Copts are History to this day called in Arabic. By the Coptic church, therefore, is meant the native church of Egypt or church of Alexandria. Its founder was St Mark, after whom was called the cathedral, which survived the Arab conquest. From St Mark the succession has been maintained to the present time, but not unbroken. Up to the 5th century the church of Alexandria played a part in the Christian world scarcely second to that of Rome : the names of Origen, Athanasius, and Cyril bear witness to her greatness. But in the time of Dioscorus, 25th patriarch, the church, always fond of speculation, was rent asunder by the controversy concerning the single or twofold nature of our Lord, as stated by Eutyches. The Eutychian doctrine, approved by the council of Ephesus, was condemned by that of Chalcedon in 451. But to this decision, though given by 636 bishops, the Copts refused assent—a refusal which profoundly affected both the religious and the political history of their country. From that moment they were treated as heretics. The emperor appointed a new bishop of Alexandria, whose adherents the Copts styled Melkites or Imperialists, while the Copts were called Monophysites and Jacobites. The court party and the native party each maintained its own line of patriarchs, and each treated the other with bitter hostility. For nearly two centuries strife and persecution continued. The well-meant ecthesis of Heraclius was a failure and was followed by repression, till in 640 the Copts found their opportunity in the Saracen invasion. The fall of the Byzantine empire meant the fall of the Byzantine church, and after some resistance the Copts accepted a change of masters, which gave them religious freedom. The orthodox or Melkite party, consisting mostly of Byzantine Greeks, was swept away, and the double succession of patriarchs practically ceased. True, even in 1901 there was an orthodox patriarch of Alexandria living in Cairo, but he had only a few Greeks for followers, and scarcely a nominal succession has been maintained. But the Coptic succession has been continuous and real. “ The most holy Pope and patriarch of the great city of Alexandria and of all the land of Egypt, of Jerusalem the holy city, of Nubia, Abyssinia, and Penta- Hierarchy polis, and all the preaching of St Mark,” as he is still called, had originally jurisdiction over all the places named. Jurisdiction over Abyssinia remains, but from Nubia and Pentapolis Christianity has disappeared. The ancient rule is that no bishop is eligible for the patriarchate. The requirement of a period of desert life has so far prevailed that no one but a monk from one of the desert monasteries is now qualified. This rule, harmless perhaps