Copper sentence example
Here are the oldest and most celebrated copper mines in Europe.
A chest of drawers with copper handles sat beside the bed - and what a bed it was.
She hadn't noticed his pallor beneath his copper skin, but she saw it now.
Connexion is made into the office (or to the underground system, as is often the case) from the aerial wire by means of a copper conductor, insulated with gutta-percha, which passes through a " leading in " cup, whereby leakage is prevented between the wire and the pole.
Kris.s eyes flared copper, then amber.Advertisement
The joists are covered with a waterproof material such as asphalt, lead, zinc or copper, the three last materials being usually laid upon boarding, which stiffens the structure and forms a good surface to fix the weatherproof covering upon.
His eyes glinted rather than flashed, his copper skin tight across perfect, chiseled features.
In Western Australia copper deposits have been worked for some years.
Gutta-percha-covered copper wires were formerly largely used for the purpose of underground lines, the copper conductor weighing 40 lb per statute mile, and the gutta-percha covering 50 lb (90 lb total).
She lifted her head, copper curls falling across her eyes.Advertisement
The satisfactory price obtained during recent years has enabled renewed attention to be paid to copper mining in South Australia, and the production of the metal in 1905 was valued at £470,324.
The advantage of the high conducting power which copper possesses Over- is of especial value in moist climates (like that of the United Kingdom), since the effect of leakage over the surface of the damp insulators is much less noticeable when the conducting power of the wire is high than when it is low, especially when the line is a long one.
This consists of a low resistance coil of copper wire enclosed in a laminated iron circuit similar to the magnetic shunt already de Magnetic scribed.
A cable is carried out from the mainland at Crookhaven for 7 m., and the outer end earthed by connexion with a copper mushroom anchor.
First as regards the transmitting part, one essential element is the antenna, aerial, or air wire, which may take a variety of forms. It may consist of a single plain or stranded copper wire upheld at the top by an insulator from a mast, chimney or building.Advertisement
Down the inner test tube pass four copper strips having platinum wires at their ends sealed through the glass.
His proposed radiator and absorber consisted of two wing-shaped plates of copper, the transmitter plates being interrupted in the centre by a spark gap, and the receiver plates by an inductance coil from the ends of which connexions were made to a coherer.
The first antenna employed consisted of 50 bare copper wires 200 ft.
Iron, coal, copper and manganese are mined.
The mineral products include silver, lead, coal, copper, and iron.Advertisement
Between London and Birmingham a paper cable 116 m long and consisting of 72 copper conductors, each weighing 150 lb per statute mile, was laid in 1900.
Each cell contains a zinc plate, immersed in a solution of zinc sulphate, and also a porous chamber containing crystals of copper sulphate and a copper plate.
The coated wire is treated in the same way as the copper strand - the die D, or another of the same size, being placed at the back of the cylinder and a larger one substituted at the front.
The coils are wound with copper wire (covered with silk), 10 mils.
The first part will be, as before, zinc to the line; at the next half stroke of the beam M will not pass through, as there is no hole in the paper; but at the third half stroke it passes through and copper is put to the line.Advertisement
In what is known as the " hybrid " form of recorder the permanent magnets are provided with windings of insulated copper wire; the object of these windings is to provide a means of " refreshing " the magnets by means of a strong current temporarily sent through the coils when required, as it has been found that, owing to magnetic leakage and other causes, the magnets tend to lose their power, especially in hot climates.
The electric arc is formed between cooled copper (positive) and carbon (negative) electrodes in an atmosphere of hydrogen or coal-gas.
The mines near the city are very productive, and thousands of men and beasts are employed in transporting lead, iron, copper, zinc and sulphur to the coast.
The conductors used for subscribers' circuits are of copper weighing from 10 to 20 lb per mile.
The chief minerals are sulphur, in the production of which Italy holds one of the first places, iron, zinc, lead; these, and, to a smaller extent, copper of an inferior quality, manganese and antimony, are successfully mined.
Lead, antimony, mercury and copper are also produced.
Chemicals sulphate of copper, employed chiefly as a preventive 01 certain maladies of the vine; carbonate of lead, hyper.
The industries are the manufacture of copper utensils and yellow leather, and the stamping of colours on white Manchester cotton.
Near Tokat copper pyrites, with iron and manganese, kaolin and coal are found; but most of the copper worked here comes from the mines of Keban Maden and Arghana Maden, on the upper Euphrates and Tigris.
Saturn for lead, Venus for copper, and Mars for iron, and the belief that the colours of flowers ' The Egyptians believed that the medicinal virtues of plants were due to the spirits who dwelt within them.
Mantegna has sometimes been credited with the important invention of engraving with the burin on copper.
Several of his engravings are supposed to be executed on some metal less hard than copper.
The other minerals found are silver, lead, copper, magnesium and lignite coal.
Cairns is the natural outlet for the gold-fields, tin-mines and silver-fields of the district and for the rich copper district of Chillagoe.
In its vivid blue colour it contrasts strikingly with the emerald-green malachite, also a basic copper carbonate, but containing rather more water and less carbon dioxide.
Azurite occurs with malachite in the upper portions of deposits of copper ore, and owes its origin to the alteration of the sulphide or of native copper by water containing carbon dioxide and oxygen.
It is thus a common mineral in all copper mines, and sometimes occurs in large masses, as in Arizona and in South Australia, where it has been worked as an ore of copper, of which element it contains 55%.
The Finland rappa-kivi, the Serdobol gneiss, and the Pargas and Rustiala marble (with the so-called Eozoon canadense) yield good building stone; while iron, copper and zinc-ore are common in Finland and in the Urals.
One of the neighbouring mines, the Proprietary, is the richest in the world; gold is associated with the silver; large quantities of lead, good copper lodes, zinc and tin are also found.
Copper and zinc have also been found.
Michoacan is essentially a mining region, producing gold, silver, lead and cinnabar, and having rich deposits of copper, coal, petroleum and sulphur.
The population is chiefly occupied in connexion with the sulphur, copper, silver and other mines in the neighbourhood.
The country has a great wealth of minerals, silver having been found, and copper, lead, iron, coal and rock-salt being wrought with profit.
Carpets (especially at Shusha), silk, cotton and woollen goods, felts and fur cloaks are made, and small arms in Daghestan and at Tiflis, Nukha and Sukhumkaleh; silversmiths' work at Tiflis, Akhaltsikh and Kutais; pottery at Elisavetpol and Shusha; leather shoe-making at Alexandropol, Nukha, Elisavetpol, Shusha and Tiflis; saddlery at Sukhum-kaleh and Ochemchiri on the Black Sea and at Temirkhan-shura in Daghestan; and copper work at Derbent and Alexandropol.
The hill ranges in Bellary are those of Sandur and Kampli to the west, the Lanka Malla to the east and the Copper Mountain (3148 ft.) to the south-west.
There are soap and flour mills and metallurgic factories in the town, and iron, copper and lead mines in the neighbouring Sierra de Almenara.
It was about this time that the value of a mixture of lime and sulphate of copper (bouillie bordelaise), sprayed in solution upon the growing plants, came to be recognized as a check upon the ravages of potato disease.
Successful trials of sulphate of copper solution as a means of destroying charlock in corn crops took place in the years 1898-1900.
The neighbourhood is rich in zinc and lead; and copper is also found.
There are copper mines, which have been worked since the 15th century, 1358 ft.
Sulphur, salt and copper are the most important of the minerals.
At some distance from the shaft a square water-tight wall was built, and the space between it and the shaft was filled in with sand, which was purified of all saline matter by repeated washings; on the ground-level perforated stones set at the four corners of the basin admitted the rain-water, which was discharged from the roofs by lead pipes; this water filtered through the sand and percolated into the shaft of the well, whence it was drawn in copper buckets.
The impurities occasionally present in commercial citric acid are salts of potassium and sodium, traces of iron, lead and copper derived from the vessels used for its evaporation and crystallization, and free sulphuric, tartaric and even oxalic acid.
The top of the still had a removable head, connected with a condenser consisting of a copper worm in a barrel of water.
The earliest form of testing instrument employed for this purpose was that of Giuseppe Tagliabue of New York, which consists of a glass cup placed in a copper water bath heated by a spirit lamp. The cup is filled with the oil to be tested, a thermometer placed in it and heat applied, the temperatures being noted at which, on passing a lighted splinter of wood over the surface of the oil, a flash occurs, and after further heating, the oil ignites.
Their sideboards were covered with the copper and silver work of Eastern smiths and the confectioneries of Damascus.
To make the ligament, a very large number of exceedingly fine copper wires laid close together are soldered to the upper surface of the upper trunnion.
The movable circuit CC thus hangs by two ligaments which are formed of very fine copper wires.
Other exports are tin and copper, granite, serpentine, vegetables and china clay.
The finest agricultural land in the United States is near the lake, and there is an immense trade in all grains, fruits, livestock and lumber, and in products such as flour, pork, hides, leather goods, furniture, &c. Rich lead and copper mines abound, as also salt, iron and coal.
Thus in the Speculum Naturale of Vincent of Beauvais (c. 1250) it is said that there are four spirits - mercury, sulphur, arsenic and sal ammoniac - and six bodies - gold, silver, copper, tin, lead and iron.
Vincent attributes to Rhazes the statement that copper is potentially silver, and any one who can eliminate the red colour will bring it to the state of silver, for it is copper in outward appearance, but in its inmost nature silver.
A mixture of carbon bisulphide vapour and sulphuretted hydrogen, when passed over heated copper, gives, amongst other products, some methane.
The mines, chiefly the property of the state and of the corporation, yield silver, gold, lead, copper and arsenic. The town contains also flourishing potteries, where well-known tobacco pipes are manufactured.
Iron ore, lignite, copper, mercury, molybdenite, nickel, platinum and other minerals have been found, but the quantity of each is too small, or the quality too poor, for them to be of commercial value.
The most important building is the Groote Kerk, of St Walpurgis, which dates from the 12th century and contains monuments of the former counts of Zutphen, a 13th-century candelabrum, an elaborate copper font (1527), and a fine modern monument to the van Heeckeren family.
Originally it owed its whole importance to the copper mines of the Parys (probably, Parry's) mountain, as, before ore was discovered in March 1768, it was a small hamlet of fishermen.
The mines once produced 3000 tons of metal annually, copper smelting being largely carried on, but have now almost ceased working.
From an analogy instituted between the healthy human being and gold, the most perfect of the metals, silver, mercury, copper, iron, lead and tin, were regarded in the light of lepers that required to be healed.
Gold, the most perfect metal, had the symbol of the Sun, 0; silver, the semiperfect metal, had the symbol of the Moon, 0j; copper, iron and antimony, the imperfect metals of the gold class, had the symbols of Venus Mars and the Earth tin and lead, the imperfect metals of the silver class, had the symbols of Jupiter 94, and Saturn h; while mercury, the imperfect metal of both the gold and silver class, had the symbol of the planet,.
Thus copper sulphate was CuO+S0 3, potassium sulphate 2S0 3 +P00 2 (the symbol Po for potassium was subsequently discarded in favour of K from kalium).
The Egyptians obtained silver, iron, copper, lead, zinc and tin, either pure or as alloys, by smelting the ores; mercury is mentioned by Theophrastus (c. 300 B.C.).
Schneider and others, have proved the existence of " colloidal silver "; similar forms of the metals gold, copper, and of the platinum metals have been described.
Wolcott Gibbs worked out the electrolytic separation of copper in 1865.
Gold and copper salts give a metallic bead without an incrustation.
The solution is filtered and treated with an excess of sulphuretted hydrogen, either in solution or by passing in the gas; this precipitates mercury (mercuric), any lead left over from the first group, copper, bismuth, cadmium, arsenic, antimony and tin as sulphides.
The precipitate formed by sulphuretted hydrogen may contain the black mercuric, lead, and copper sulphides, dark-brown bismuth sulphide, yellow cadmium and arsenious sulphides, orange-red antimony sulphide, brown stannous sulphide, dull-yellow stannic sulphide, and whitish sulphur, the last resulting from the oxidation of sulphuretted hydrogen by ferric salts, chromates, &c. Warming with ammonium sulphide dissolves out the arsenic, antimony and tin salts, which are reprecipitated by the addition of hydrochloric acid to the ammonium sulphide solution.
Filter from the bismuth hydrate, and if copper is present, add potassium cyanide till the colour is destroyed, then pass sulphuretted hydrogen, and cadmium is precipitated as the yellow sulphide.
If copper is absent, then sulphuretted hydrogen can be passed directly into the solution.
In acid copper solutions, mercury is deposited before the copper with which it subsequently amalgamates; silver is thrown down simultaneously; bismuth appears towards the end; and after all the copper has been precipitated, arsenic and antimony may be deposited.
Carbon is detected by the formation of carbon dioxide, which turns lime-water milky, and hydrogen by the formation of water, which condenses on the tube, when the substance is heated with copper oxide.
Beilstein determines their presence by heating the substance with pure copper oxide on a platinum wire in the Bunsen flame; a green coloration is observed if halogens be present.
The oxidizing agent in commonest use is copper oxide, which must be freshly ignited before use on account of its hygroscopic nature.
The space a must allow for the inclusion of a copper spiral if the substance contains nitrogen, and a silver spiral if halogens be present, for otherwise nitrogen oxides and the halogens may be condensed in the absorption apparatus; b contains copper oxide; c is a space for the insertion of a porcelain or platinum boat containing a weighed quantity of the substance; d is a copper spiral.
After having previously roasted the tube and copper oxide, and reduced the copper spiral a, the weighed calcium chloride tube and potash bulbs are put in position, the boat containing the substance is inserted (in the case of a difficultly combustible substance it is desirable to mix it with cupric oxide or lead chromate), the copper spiral (d) replaced, and the air and oxygen supply connected up. The apparatus is then tested for leaks.
If all the connexions are sound, the copper oxide is gradually heated from the end a, the gas-jets under the spiral d are lighted, and a slow current of oxygen is passed through the tube.
Nitrogen is estimated by (I) Dumas' method, which consists in heating the substance with copper oxide and measuring the volume Nitrogen.
The magnesite (a) serves for the generation of carbon dioxide which clears the tube of air before the compound (mixed with fine copper oxide (b)) is burned, and afterwards sweeps the liberated nitrogen into the receiving vessel (e), which contains a strong potash solution; c is coarse copper oxide; and d a reduced copper gauze spiral, heated in order to decompose any nitrogen oxides.
Substances which burn with difficulty may be mixed with mercuric oxide in addition to copper oxide.
The Sumerians cast the heads of their lions in copper, not always with successful results, and filled them with bitumen and clay (like the image in " Bel and the Dragon," which was " clay within and brass without ") to give them solidity.
The question as to whether copper really was first used in Egypt is not yet resolved, and many arguments can be brought against the theory of Egyptian origin and in favour of one in Syria or further north.26 Egypt has also recently been credited with being the inceptor of the whole " megalithic (or heliolithic, as the fashionable word now is) culture " of mankind, from Britain to China and (literally) Peru or at any rate Mexico via the Pacific Isles.27 The theory is that the achievements of the Egyptians in great stone architecture at the time of the pyramid-builders so impressed their contemporaries that they were imitated in the surrounding lands, by the Libyans and Syrians, that the fame of them was carried by the Phoenicians further afield, and that early Arab and Indian traders passed on the megalithic idea to Farther India, and thence to Polynesia and so on so that both the teocalli of Teotihuacan and Stonehenge are ultimately derived through cromlechs and dolmens innumerable from the stone pyramid of Saqqara, built by Imhotep, the architect of King Zoser, about 3100 B.C. (afterwards deified as the patron of science and architecture).
Those in the Rudimentum novitiarum published at Lubeck in 1475 are from woodcuts, while the maps in the first two editions of Ptolemy published in Italy in 1472 are from copper plates.
Wood engraving kept its ground for a considerable period, especially in Germany, but copper in the end supplanted it, and owing to the beauty and clearness of the maps produced by a combination of engraving and etching it still maintains its ground.
The objection that a copper plate shows signs of wear after a thousand impressions have been taken has been removed, since duplicate plates are readily produced by electrotyping, while transfers of copper engravings, on stone, zinc or aluminium, make it possible to turn out large editions in a printing-machine, which thus supersedes the slow-working hand-press.
A copper plate having been coated with wax, outline and ornament are cut into the wax, the lettering is impressed with type, and the intaglio thus produced is electrotyped.
The original drawings for this map had to be done with exceptional neatness, the draughtsman spending twelve months on that which he would have completed in four months had it been intended to engrave the map on copper; yet an average chart, measuring 530 by 630 mm., which would have taken two years and nine months for drawing and engraving, was completed in less than fifteen months - fifty days of which were spent in " retouching " the copper plate.
The geographical ideas which prevailed at the time Columbus started in search of Cathay may be most readily gathered from two contemporary globes, the one known as the Laon globe because it was picked up in 1860 at a curiosity shop in that town, the other produced at Nuremberg in 1492 by Martin Behaim.1 The Laon globe is of copper gilt, and has a diameter of 170 mm.
Mercator's maps are carefully engraved on copper.
Originally the maps were engraved on copper, and the progress of publication was slow; but since the introduction of modern processes, such as electrotyping (in 1840), photography (in 1855) and zincography (in 1859), it has been rapid.
It is engraved on copper.
The earlier sheets of this excellent map were lithographed, but these are gradually being superseded by maps engraved on copper.
Large copper deposits of peculiar richness occur here in the Sierra de Cobre, near the city of Santiago; and both iron and manganese are abundant.
Besides the deposits in Oriente province, iron is known to exist in considerable amount in Camaguey and Santa Clara, and copper in Camaguey and Pinar del Rio provinces.
The Cobre copper mines near Santiago were once the greatest producers of the world.
The " Cobre " mine is only the most famous and productive of various copper properties.
The copper output has not greatly increased since 1890, and is of slight importance in mineral exports.
The other industries are leather work, sugar-refining, goldsmith's work, ivory carving, iron, brass, copper, stone masonry, tanning, weaving, dyeing and carpentry.
This may be effected by burning phosphorus in a confined volume of air, by the action of an alkaline solution of pyrogallol on air, by passing air over heated copper, or by the action of copper on air in the presence of ammoniacal solutions.
It is very unstable, decomposing into nitrous oxide and water when mixed with copper oxide, lead chromate or even powdered glass.
Bosnia is rich in minerals, including coal, iron, copper, chrome, manganese, cinnabar, zinc and mercury, besides marble and much excellent building stone.
The empire is rich in minerals, including gold, silver, lead, copper, iron, coal, mercury, borax, emery, zinc; and only capital is needed for successful exploitation.
The silver, lead and copper mines are mainly worked by British capital.
Finally, usage of paper money was restricted to the capital only, and in 1842 this partial reform of the paper currency was followed by a reform of the metallic currency, in the shape of an issue of gold, silver and copper currency of good value.
The copper money was in pieces of a nominal value of 40, 20, TO, 5 and i paras, 40 paras being equal to 1 piastre.
Its chief exports are rubber, gum, coffee and copper.
A few other minerals may be noticed, and some have been worked to a small extent - graphite is abundant, particularly near Upernivik; cryolite is found almost exclusively at Ivigtut; copper has been observed at several places, but only in nodules and laminae of limited extent; and coal of poor quality is found in the districts about Disco Bay and Umanak Fjord.
Copper works were established here in 1866, followed long after by tinstamping and enamel works.
Callias And Hipponicus The exports from Callao are guano, sugar, cotton, wool, hides, silver, copper, gold and forest products, and the imports include timber and other building materials, cotton and other textiles, general merchandise for personal, household and industrial uses, railway material, coal, kerosene, wheat, flour and other food stuffs.
An important nucleo-proteid is haemoglobulin or haemoglobin, the colouring matter of the red blood corpuscles of vertebrates; a related substance, haemocyanin, in which the iron of haemoglobin is replaced by copper, occurs in the blood of cephalopods and crayfish.
They manufacture copper boilers for making sugar and understand several trades, weave ponchos and hammocks and make straw hats.
As an example we may take the case of a solution of a salt such as copper sulphate in water, through which an electric current is passed between copper plates.
Volta's cell consists essentially of two plates of different metals, such as zinc and copper, connected by an electrolyte such as a solution of salt or acid.
Soon afterwards, William Cruickshank decomposed the magnesium, sodium and ammonium chlorides, and precipitated silver and copper from their solutions - an observation which led to the process of electroplating.
In batteries which use acids as the electrolyte, a film of hydrogen tends to be deposited on the copper or platinum electrode; but, to obtain a constant electromotive force, several means were soon devised of preventing the formation of the film.
Constant cells may be divided into two groups, according as their action is chemical (as in the bichromate cell, where the hydrogen is converted into water by an oxidizing agent placed in a porous pot round the carbon plate) or electrochemical (as in Daniell's cell, where a copper plate is surrounded by a solution of copper sulphate, and the hydrogen, instead of being liberated, replaces copper, which is deposited on the plate from the solution).
Now this ratio is the same as that which gives the relative chemical equivalents of hydrogen and copper, for r gramme of hydrogen and 31.8 grammes of copper unite chemically with the same weight of any acid radicle such as chlorine or the sulphuric group, SO 4.
All copper salts in dilute solution are blue, which is therefore the colour of the copper ion.
Solid copper chloride is brown or yellow, so that its concentrated solution, which contains both ions and undissociated molecules, is green, but changes to blue as water is added and the ionization becomes complete.
As an example of a fairly constant cell we may take that of Daniell, which consists of the electrical arrangement - zinc zinc sulphate solution copper sulphate solution copper, - the two solutions being usually separated by a pot of porous earthenware.
When the zinc and copper plates are connected through a wire, a current flows, the conventionally positive electricity passing from copper to zinc in the wire and from zinc to copper in the cell.
Zinc dissolves at the anode, an equal amount of zinc replaces an equivalent amount of copper on the other side of the porous partition, and the same amount of copper is deposited on the cathode.
This process involves a decrease in the available energy of the system, for the dissolution of zinc gives out more energy than the separation of copper absorbs.
But the internal rearrangements which accompany the production of a current do not cause any change in the original nature of the electrodes, fresh zinc being exposed at the anode, and copper being deposited on copper at the cathode.
Thus as long as a moderate current flows, the only variation in the cell is the appearance of zinc sulphate in the liquid on the copper side of the porous wall.
In spite of this appearance, however, while the supply of copper is maintained, copper, being more easily separated from the solution than zinc, is deposited alone at the cathode, and the cell remains constant.
Thus in the Daniell cell the dissolution of copper as well as of zinc would increase the loss in available energy.
If the external electromotive force exceed that of the cell by ever so little, a current flows in the opposite direction, and all the former chemical changes are reversed, copper dissolving from the copper plate, while zinc is deposited on the zinc plate.
Similarly, the heat which accompanies the dissolution of one electrochemical unit of copper is 3.00 calories.
Again, Hittorf has shown that the effect of a cyanide round a copper electrode is to combine with the copper ions.
The concentration of the simple copper ions is then so much diminished that the copper plate becomes an anode with regard to zinc. Thus the cell - copper I potassium cyanide solution I potassium sulphate solution - zinc sulphate solution I zinc - gives a current which carries copper into solution and deposits zinc. In a similar way silver could be made to act as anode with respect to cadmium.
Hence, if we assume that, in the Daniell's cell, the temperature coefficients are negligible at the individual contacts as well as in the cell as a whole, the sign of the potential-difference ought to be the same at the surface of the zinc as it is at the surface of the copper.
Since zinc goes into solution and copper comes out, the electromotive force of the cell will be the difference between the two effects.
By both these methods the single potential-differences found at the surfaces of the zinc and copper have opposite signs, and the effective electromotive force of a Daniell's cell is the sum of the two effects.
Copper is mined and extensive deposits of petroleum and asphalt are being exploited.
If a glucose solution be added to copper sulphate and much alkali added, a yellowish-red precipitate of cuprous hydrate separates, slowly in the cold, but immediately when the liquid is heated; this precipitate rapidly turns red owing to the formation of cuprous oxide.
Barreswil found that a strongly alkaline solution of copper sulphate and potassium sodium tartrate (Rochelle salt) remained unchanged on boiling, but yielded an immediate precipitate of red cuprous oxide when a solution of glucose was added.
Iron ships' plates have recently been coated with copper in sections (to prevent the adhesion of barnacles), by building up a temporary trough against the side of the ship, making the thoroughly cleansed plate act both as cathode and as one side of the trough.
For this reason the acid copper-bath is not used for iron or zinc objects, a bath containing copper cyanide or oxide dissolved in potassium cyanide being substituted.
In the deposition of gold the colour of the deposit is influenced by the presence of impurities in the solution; when copper is present, some is deposited with the gold, imparting to it a reddish colour, whilst a little silver gives it a greenish shade.
The electro-deposition of brass-mainly on iron ware, such as bedstead tubes-is now very widely practised, the bath employed being a mixture of copper, zinc and potassium cyanides, the proportions of which vary according to the character of the brass required, and to the mode of treatment.
The colour depends in part upon the proportion of copper and zinc, and in part upon the current density, weaker currents tending to produce a redder or yellower metal.
For example, Wilde produced copper printing surfaces for calico printing-rollers and the like by immersing rotating iron cylinders as cathodes in a copper bath.
Elmore, Dumoulin, Cowper-Coles and others have prepared copper cylinders and plates by depositing copper on rotating mandrels with special arrangements.
Silver and lead ores exist in the Altai and the Nerchinsk Mountains, as well as, copper, cinnabar and tin.
The tube is made of glass, indiarubber, copper or lead, according to the liquid which is to be transferred.
Galena occurs in veins in the Cambrian clay-slate, accompanied by copper and iron pyrites, zinc-blende, quartz, calcspar, iron-spar, &c.; also in beds or nests within sandstones and rudimentary limestones, and in a great many other geological formations.
Of the impurities, most of the copper, nickel and copper, considerable arsenic, some antimony and small amounts of silver are removed by liquation.
When zinc is placed on the lead (heated to above the melting-point of zinc), liquefied and brought into intimate contact with the lead by stirring, gold, copper, silver and lead will combine with the zinc in the order given.
Pure lead is far more readily corroded than a metal contaminated with 1% or even less of antimony or copper.
Powdered galena is dissolved in hot hydrochloric acid, the solution allowed to cool and the deposit of impure lead chloride washed with cold water to remove iron and copper.
Heusler that an alloy consisting of copper, aluminium and manganese (Heusler's alloy), possesses magnetic qualities comparable with those of iron.
The metal to be tested was prepared in the form of a ring, upon which were wound primary and secondary coils of copper wire insulated with asbestos.
As in Hopkinson's experiments, ring magnets were employed; these were wound with primary and secondary coils of insulated platinum wire, which would bear a much higher temperature than copper without oxidation or fusion.
The metals used in different combinations included tin, aluminium, arsenic, antimony, bismuth and boron; each of these, when united in certain proportions with manganese, together with a larger quantity of copper (which appears to serve merely as a menstruum), constituted a magnetizable alloy.
Thus in an alloy containing 26.5% of manganese and 14.6% of aluminium, the rest being copper, the induction for H= 20 was 4500, and for H=150, 5550.
In the second series, to which greater importance is attached, measurements were made of the force exerted in a divergent field upon small balls of copper, silver and other substances, first when the balls were in air and afterwards when they were immersed in liquid oxygen.
The chief exports are chestnut extract for tanning, cedrates, citrons, oranges, early vegetables, fish, copper ore and antimony ore.
Attempts to mine the copper followed, and the prospectors and hunters who penetrated northward sent to the Cape reports of the existence of a great river whose waters always flowed.
For his account of earlier events he was able to obtain information from his father, who was one of the most prominent 1 A shortened form of Chalcocondyles, from xaXicos, copper, and xovSvXos, knuckle.
The town is noted for its copper utensils, but the famous copper mines about 36 m.
Among the minerals are silver, platinum, copper, iron, lead, manganese, chromium, quicksilver, bismuth, arsenic and antimony, of which only iron and manganese have been regularly mined.
The copper deposits of Minas Geraes are said to be promising.
There are extensive copper and goldyielding areas, and in some districts these metals are mined.
It successfully resisted the attacks of Hannibal; and it is noteworthy that it continued to strike copper coins even under Augustus and Tiberius.
Its chief mineral products are coal, nitre, sulphur, alum, soda, saltpetre, gypsum, porcelain-earth, pipe-clay, asphalt, petroleum, marble and ores of gold, silver, mercury, copper, iron, lead, zinc, antimony, cobalt and arsenic. The principal mining regions are Zsepes-Giimor in Upper Hungary, the Kremnitz-Schemnitz district, the Nagybanya district, the Transylvanian deposits and the Banat.
Of agricultural produce there was barely sufficient for home consumption, but the mining industries had reached a very high level of excellence, and iron, tin and copper were very largely exported from the northern counties to Danzig and other Baltic ports.
A Chinese garrison is stationed here, and copper and iron are wrought in the neighbourhood by exiled Chinese criminals.
Small up to the beginning of the 19th century, Holywell has increasingly prospered, thanks to lime quarries, lead, copper and zinc mines, smelting works, a shot manufactory, copper, brass, iron and zinc works; brewing, tanning and mineral water, flannel and cement works.
In front of the naked eye was held a piece of copper foil perforated by a fine needle hole.
The earliest is that of Quincke, who coated a glass grating with a chemical silver deposit, subsequently thickened with copper in an electrolytic bath.
The chief divergence is in the presence of silver and copper objects, but the great quantity of gold is the most striking fact, and to say that there was nothing but gold seems merely an exaggeration.
Mieres is the chief town of a mountainous, fertile and well-wooded region in which coal, iron, and copper are extensively mined and sulphur and cinnabar are obtained in smaller quantities.
From the solution the arsenic, copper, &c., are precipitated by sulphuretted hydrogen as sulphides, which are filtered off.
Gold, lead, copper and iron ores occur as veins.
The minerals chiefly mined besides gold are diamonds and coal, but the country possesses also silver, iron, copper, lead, cobalt, sulphur, saltpetre and many other mineral deposits.
Iron and copper are widely distributed.
Next in value came wool (£226,000), horses and mules (£110,000), skins, hides and horns (£106,000), tobacco (£89,000), tin, coal, copper and lead.
The "tin" of the Bible (KauoLTEpos in the Septuagint) corresponds to the Hebrew bedhil, which is really a copper alloy known as early as 1600 B.C. in Egypt.
The slag and metal produced are then run off and the latter is cast into bars; these are in general contaminated with iron, arsenic, copper and other impurities.
Iron renders the metal hard and brittle; arsenic, antimony and bismuth (up to 0.5%) reduce its tenacity; copper and lead (1 to 2%) make it harder and stronger but impair its malleability; and stannous oxide reduces its tenacity.
But it is expensive, and tin vessels have to be made very heavy to give them sufficient stability of form; hence it is generally employed merely as a protecting coating for utensils made essentially of copper or iron.
The tinning of a copper basin is an easy operation.
The district of which Cobar is the centre abounds in minerals of all kinds, but copper and gold are those most extensively worked.
The principal minerals are gold, copper, iron, sulphur, coal, asphalt and petroleum.
There are 14 copper mines in the country, those at Aroa, 70 m.
The mineral resources include gold, silver, copper and petroleum, but no mines were in operation in 1906.
The mineral wealth is great, including copper, tin, lead, zinc, iron and especially coal.
Leber experimented with several chemical compounds to find what reaction they had on these cells; by using fine glass tubes sealed at the outer end and containing a chemical substance, and by introducing the open end into the blood vessels he found that the leucocytes were attracted - positive chemiotaxis - by the various compounds of mercury, copper, turpentin, and other substances.
Certain peculiar substances, probably degenerative products, some of them reducing copper, are occasionally met with.
The mineral resources include silver, gold, copper, lead, tin, iron and coal, and mining is the chief industry.
Gold, iron, copper and other minerals have also been found, but the mineral wealth of the country is undeveloped.
Other metals, such as manganese, copper, nickel, may show their presence by characteristic colours.
In mines of copper, lead and the precious metals, in which the cars are moved by hand, the usual load is from 1200 to 3000 lb.
Skips are sometimes of very large capacity, holding 5, 7, and even 10 tons of ore; such are used, for example, in several shafts at Butte, Montana, in the Lake Superior copper district, and in South Africa.
Such cars are in use at a number of deep inclined shafts in the Lake Superior copper district, where the depths range from 3000 to 5000 ft.
Similar swelling ground is not infrequently met with in metal mines, as, for example, in the Phoenix copper mine in Houghton county, Michigan, where the force developed was sufficient to crush the strongest timber that could be used.
Copper gives a peacock-blue which becomes green if the proportion of the copper oxide is increased.
If oxide of copper is added to a glass mixture containing a strong reducing agent, a glass is produced which when first taken from the crucible is colourless but on being reheated develops a deep crimson - ruby colour.
A similar glass, if its cooling is greatly retarded, produces throughout its substance minute crystals of metallic copper, and closely resembles the mineral called avanturine.
Glass containing gold behaves in almost precisely the same way, but the ruby glass is less crimson than copper ruby glass.
Engraving is a process of drawing on glass by means of small copper wheels.
Avanturine glass, that in which numerous small particles of copper are diffused through a transparent yellowish or brownish mass, was not invented until about 1600.
It decomposes solutions of silver nitrate and copper sulphate.
Many are found as minerals, the more important of such naturally occurring carbonates being cerussite (lead carbonate, PbC03), malachite and azurite (both basic copper carbonates), calamine (zinc carbonate, ZnCO 3), witherite (barium carbonate, BaCO 3), strontianite (strontium carbonate, SrC03), calcite (calcium carbonate, CaC03), dolomite (calcium magnesium carbonate, CaCO 3 MgCO 3), and sodium carbonate, Na 2 CO 3.
Most metals form carbonates (aluminium and chromium are exceptions), the alkali metals yielding both acid and normal carbonates of the types Mhco 3 and M 2 CO 3 (M = one atom of a monovalent metal); whilst bismuth, copper and magnesium appear only to form basic carbonates.
Originally applied to gold, silver, copper, iron, tin, lead and bronze, i.e.
Very thin films of liquid mercury, according to Melsens, transmit light with a violet-blue colour; also thin films of copper are said to be translucent.
Gold is yellow; copper is red; silver, tin, and some others are pure white; the majority are greyish.
Gold, silver, copper, lead, aluminium, cadmium, iron (pure), nickel and cobalt are practically amorphous, the crystals (where they exist) being so closely packed as to produce a virtually homogeneous mass.
Pure iron, copper, silver and other metals are easily drawn into wire, or rolled into sheet, or flattened under the hammer.
He operated with lead, copper, silver, iron and some other metals.
Mercury and copper and some other metals are capable of dissolving their own oxides.
Copper, when pure to start with, suffers considerable deterioration in plasticity.
Alloys of copper and silicon were prepared by Deville in 1863.
Copper, in the present connexion, is intermediate between iron and the following group of metals.
A group (B), comprising copper, is, substantially, attacked only in the presence of oxygen or air.
Potassium, for example, yields peroxide, K202 or K204; sodium gives Na202; the barium-group metals, as well as magnesium, cadmium, zinc, lead, copper, are converted into their monoxides MeO.
Of the heavy metals, copper is the one which exhibits by far the greatest avidity for sulphur, its subsulphide Cu 2 S being the stablest of all heavy metallic sulphides in opposition to dry reactions.
The ultimate chlorination product of copper, CuC1 2, when heated to redness, decomposes into the lower chloride, CuCI, and chlorine.
The most striking development in the resources of the country from 1909 was the exploitation of the copper mines of Katanga.
The output of copper rose from 997 tons in 1911 to 27,462 tons in 1917; it was 22,000 tons in 1919 and 19,000 tons in 1920.
Up to the outbreak of the World War all the Katanga copper was bought by Germans; thereafter it was sent to Britain.
Next in importance to copper mining was the development of the palm-oil industry, which up to 1911 had been practically confined to the Mayumba district.
From 1914 onward copper and palm kernels and oil were the chief exports.
An experiment was devised by Lord Kelvin for demonstrating this, in which the difference of steadiness was shown of a copper shell filled with liquid and spun gyroscopically, according as the shell was slightly oblate or prolate.
Contract tablets have been found dated in the years of the campaigns against Palestine and Sarlak, king of Gutium or Kurdistan, and copper is mentioned as being brought from Magan or the Sinaitic peninsula.
Gudea was also a great builder, and the materials for his buildings and statues were brought from all parts of western Asia, cedar wood from the Amanus mountains, quarried stones from Lebanon, copper from northern Arabia, gold and precious stones from the desert between Palestine and Egypt, dolerite from Magan (the Sinaitic peninsula) and timber from Dilmun in the Persian Gulf.
Copper, too, was worked with skill; indeed, it is possible that Babylonia was the original home of copper-working, which spread westward with the civilization to which it belonged.
This disease has been successfully treated with a spray of copper sulphate and lime, or sulphate of iron; solutions of these salts prevent the conidia from germinating.
As a preventive to its attacks the copper sulphate sprays and a solution (50%) of iron sulphate have been found very useful, as well as care in planting on well-drained soil that does not lie too low, the disease seldom appearing in dry, well-exposed vineyards.
The use of the copper solutions mentioned above may also be recommended as a preventive.
Copper smelting has been carried on in or near the town since 1584 when the Mines Royal Society set up works at Neath Abbey; the industry attained huge proportions a century later under Sir Humphrey Mackworth, who from 16 9 5 carried on copper and lead smelting at Melincrythan.
Besides its copper works the town at present possesses extensive tinplate, steel and galvanized sheet works as well as iron and brass foundries, steam-engine factories, brick and tile works, engineering works, flannel factories and chemical works.
There is a large export trade in coal, I copper, iron and tin, mostly shipped from nieghbouring ports, while the principal imrorts are timber and general merchandise.
It reduces ammoniacal silver solutions in the cold, and alkaline copper solutions on boiling.
This defecator is made with a hemispherical copper bottom, placed in.
This is attained by the aid of a copper pipe, 4 in.
Earthy matter and other matter precipitated and fallen on the copper double bottom may be dislodged by a slowly revolving scraper - say every twelve hours - and ejected through the bottom discharge cock; and thus the heating surface of the copper bottom will be kept in full efficiency.
In former days, when refining sugar or " sugar baking " was supposed to be a mystery only understood by a few of the initiated, there was a place in the refinery called the " secret room," and this name is still used in some refineries, where, however, it applies not to any room, but to a small copper cistern, constructed with five or six or more divisions or small canals, into which all the charcoal cisterns discharge their liquors by pipes led up from them to the top of the cistern.
There is considerable agricultural trade, and iron founding is carried on; while in the neighbourhood some copper, lead, granite and slate are worked and exported in small vessels; coal, timber and general merchandise being imported.
It resembles acetylene in yielding metallic derivatives with ammoniacal copper and silver solutions.
Gold is found in the valley of the Diahot, as well as lead and copper at Balade.
Pliny explicitly speaks of a mineral Katiµ€ia or cadmic as serving for the conversion of copper into aurichalcum, and says further that the deposit (of zinc oxide) formed in the brass furnaces could be used instead of the mineral.
Stahl, as late as 1702, quoted the formation of brass as a case of the union of a metal with an earth into a metallic compound; but he subsequently adopted the view propounded by Kunckel in 1677, that "cadmia" is a metallic calx, and that it dyes the copper yellow by giving its metal up to it.
A rod of perfectly pure zinc, when immersed in dilute sulphuric acid, is so very slowly attacked that there is no visible evolution of gas; but, if a piece of platinum, copper or other more electro-positive metal be brought into contact with the zinc, it dissolves readily, with evolution of hydrogen and formation of the sulphate.
These and the ancient copper workings were investigated by Burton in 1877.
Aluminium bronze (aluminium and copper) and ferro-aluminium (aluminium and iron) have been made in this way; the latter is the more satisfactory product, because a certain proportion of carbon is expected in an alloy of this character, as in ferromanganese and cast iron, and its presence is not objectionable.
This head slides freely in the cast iron tubes, and is connected by a copper rod with one of the terminals of the dynamo supplying the current.
A sheet iron case is then placed within the furnace, and the space between it and the walls rammed with limed charcoal; the interior is filled with fragments of the iron or copper to be alloyed, mixed with alumina and coarse charcoal, broken pieces of carbon being placed in position to connect the electrodes.
The Germans recognized the staple rights of Bruges for a number of commodities, such as wool, wax, furs, copper and grain, and in return for this material contribution to the growing commercial importance of the town, they received in 1309 freedom from the compulsory brokerage which Bruges imposed on foreign merchants.
Scandinavia had early been sought for its copper and iron, its forest products and its valuable fisheries, especially of herring at Schonen, but it was backward in its industrial development and its own commerce had seriously declined in the 14th century.
The smaller Copper Island lies near.
A hydrated form is prepared when a solution of titanic acid in hydrochloric acid is digested with copper, or when the trichloride is precipitated with alkalis.
The export of coal in that year was 74,000 tons, and copper ore 937 tons (vide supra, § Minerals).
The principal exports are olive oil, wheat, esparto grass, barley, sponges, dates, fish (especially tunny), hides, horses, wool, phosphates, copper, zinc and lead.
The use of bronze also shows that they must have worked, perhaps superficially, some of the great copper deposits.
Within these limits are to be found most of the minerals known - gold, silver, quicksilver, copper, lead, zinc, iron, manganese, wolfram, bismuth, thorium, vanadium; mica, coal, &c. On or near the coast are coal, salt, sulphur, borax, nitrates and petroleum.
The Cerro de Pasco mines are supposed by some authorities to be the largest copper deposit in the world.
In addition to the smelting works at Cerro de Pasco there are other large works at Casapalca, between Oroya and Lima, which belong to a British company, and smaller plants at Huallanca and Huinac. The production of copper is steadily increasing, the returns for 1903 being 9497 tons and for 1906 13,474 tons, valued respectively at £476,824 and £996,055.
The single gold standard has been in force in Peru since 1897 and 1898, silver and copper being used for subsidiary coinage.
The silver coinage consists of the sol (100 cents), half sol (50 cents), and pieces of 20 (peseta), so and 5 cents; and the copper coinage of 1 and 2 cents.
Of other common types of condenser, we may notice the "spiral" or "worm" type, which consists of a glass, copper or tin worm enclosed in a vessel in which water circulates; and the ball condenser, which consists of two concentric spheres, the vapour passing through the inner sphere and water circulating in the space between this and the outer (in another form the vapour circulates in a shell, on the outside and inside of which water circulates).
A common type of condenser consists of a copper worm placed in a water bath; but more generally straight tubes of copper or cast iron which cross and recross a rectangular tank are employed, since this form is more readily repaired and cleansed.
The body of the still is made of copper, with a head and worm, or condensing apparatus, either of copper or tin.
I I consists of a cylindrical vessel having in its lower half a horizontal copper coil connected to the steam supply.
The chief industries are sugar-refining, the manufacture of cement, paper, bamboo and rattan ware, carving in wood and ivory, working in copper and iron, gold-beating and the production of gold, silver and sandal-wood ware, furniture making, umbrella and j;nricksha making, and industries connected with kerosene oil and matches.
There are small silver and copper coins, which are legal tenders for amounts not exceeding two dollars and one dollar respectively.
There are large copper-smelting establishments in the city, which exports a very large amount of copper, some gold and silver, and cattle and hay to the more northern provinces.
The mineral resources include extensive deposits of copper, and some less important mines of gold and silver.
The province contains gold, silver, copper, iron, lead, coal and salt, but mining has never been developed to any extent.
Cereals, cotton, forest products, cattle, and hides, and brass and copper vessels are the chief exports from the district.
Copper is the most important of the minerals worked.
Lead is of frequent occurrence, and indeed the area through which copper, silver, lead, tin and zinc are distributed in sufficient quantities to make mining answer, comprises at least 80,000 sq.
Cotton yarn and cloth, petroleum, timber and furs are among the chief imports; copper, tin, hides and tea are important exports; medicines in the shape not only of herbs and roots, but also of fossils, shells, bones, teeth and various products of the animal kingdom; and precious stones, principally jade and rubies, are among the other exports.
Silver, gold, copper, mercury, lead, tin, antimony and precious stones are found, in some cases in very rich deposits.
Old schists, free from fossils and rich in quartz, overlie it in parallel chains through the whole length of the peninsula, especially in the central and highest ridges, and bear the ores of Chu-goku (the central provinces), principally copper pyrites and magnetic pyrites.
Of the last there are two species, the kiji proper, a bird presenting no remarkable features, and the copper pheasant, a magnificent bird with plumage, of dazzling beauty.
Although a little engraving on copper has been practised in Japan of late years, it is of no artistic value, and the only branch of the art which calls for recognition is the Engraving.
Neither metal, when it emerges from the furnace, has any beauty, shakudo being simply dark-colored copper and shibuichi pale gun-metal.
Copper, too, by patina-producing treatment, is made to show not merely a rich golden sheen with pleasing limpidity, but also red of various hues, from deep coral to light vermilion, several shades of grey, and browns of numerous tones from dead-leaf to chocolate.
Evidently the idea of the great Yokoya experts, the originators of the style, was to break away from the somewhat formal monotony of ordinary engraving, where each line performs exactly the same function, and to convert the chisel into an artists i It is first boiled in a lye obtained by lixiviating wood ashes; it is next polished with charcoal powder; then immersed in plum vinegar and salt; then washed with weak lye and placed in a, tub of water to remove all traces of alkali, the final step being to digest in a boiling solution of copper sulphate, verdigris and water.
Copper, tin, lead and zinc, mixed in various proportions by different experts, are the ingredients, and the beautiful golden hues and glossy texture of the surface are obtained by patina-producing processes, in which branch of metal-work the Japanese show altogether unique skill.
A thatched roof is imperative in the orthodox shrine, but in modern days tiles or sheets of copper are sometimes substituted.
The base, usually of copper, was as thin as cardboard; the cloisons, exceedingly fine and delicate, were laid on with care and accuracy; the colors were even, and the designs showed artistic judgment.
But to spread and fix the enamel so that neither at the rim nor in the interior shall there be any break of continuity, or any indication that the base is copper, not porcelain, demands quite exceptional skill.
The mineral wealth of Baden is not great; but iron, coal, zinc and lead of excellent quality are produced, and silver, copper, gold, cobalt, vitriol and sulphur are obtained in small quantities.
The other volumes dealt with (a) iron and steel, (b) copper and brass, their smelting, conversion and assaying, and chemical experiments thereon.
Its other mineral resources include graphite, copper, zinc, lead, salt, alum, potter's clay, marble and good mill and building stones.
For details of the practical methods see Gold; Silver; Copper and headings for other metals.
The silver and copper mines of the province are numerous, some of them ranking among the most productive known, but the majority are worked with limited capital and on a small scale.
The exports include copper and silver and their ores, nitrate of soda, borax, guano and other minerals in small quantities.
It may conveniently be extended to similar mixtures of sulphur and selenium or tellurium, of bismuth and sulphur, of copper and cuprous oxide, and of iron and carbon, in fact to all cases in which substances can be made to mix in varying proportions without very marked indication of chemical action.
If we melt copper and add to it about 30% of zinc, or 20 of tin, we obtain uniform liquids which when solidified are the well-known substances brass and bell-metal.
The difference in the appearance of brass and copper is familiar to everyone; brass is also much harder than copper and much more suitable for being turned in a lathe.
The acid used to etch the surface has darkened the parts richest in copper, while those richest in tin remained white.
The two ingredients revealed by this process are not pure copper and pure tin, but each material contains both metals.
Dark parts are rich in copper, light parts in tin.
Blacks rich, whites less rich in copper.
Fromm have shown that alloys may be precipitated from dilute solutions by zinc, cadmium, tin, lead and copper.
Thus a strip of zinc plunged into a solution of silver sulphate, containing not more than 0.03 gramme of silver in the litre, becomes covered with a flocculent precipitate which is a true alloy of silver and zinc, and in the same way, when copper is precipitated from its sulphate by zinc, the alloy formed is brass.
A very similar fact, that brass may be formed by electrodeposition from a solution containing zinc and copper, has long been known.
The phenomena which succeed each other are then very similar, whether A and B are two metals, such as lead and tin or silver and copper, or are a pair of fused salts, or are water and common salt.
The dark, regularly oriented crystal skeletons were already solid at the moment of chilling; they are rich in copper.
It also possesses a splendid purple Here, the large dark masses are the silver or silver-rich substance that crystallized above the eutectic temperature, and the more minute black and white complex represents the eutectic. It is not safe to assume that the two ingredients we see are pure silver and pure copper; on the contrary, there is reason to think that the crystals of silver contain some copper uniformly diffused through them, and vice versa.
It is, however, not possible to detect the copper in the silver by means of the microscope.
This uniform distribution of a solid substance throughout the mass of another, so as to form a homogeneous material, is called " solid solution," and we may say that solid silver can dissolve copper.
This is the case with the copper-tin alloys containing less than 9% by weight of tin; a microscopic examination reveals only one material, a copper-like substance, the tin having disappeared, being in solution in the copper.
We thus learn that the bronzes referred to above, although chemically uniform when solid, are not so when they begin to solidify, but that the liquid deposits crystals richer in copper than itself, and therefore that the residual liquid becomes richer in tin.
This is so when gold and silver are alloyed with each other, and is true in the case of alloys of copper.
Alloyed with copper, it is used for the envelopes of bullets.
Manganese not only forms with iron several alloys of great interest, but alloyed with copper it is used for electrical purposes, as an alloy can thus be obtained with an electrical resistance that does not alter with change of temperature; this alloy, called manganin, is used in the construction of resistance-boxes.
One of the most interesting amongst recent alloys is Conrad Heusler's alloy of copper, aluminium and manganese, which possesses magnetic properties far in excess of those of the constituent metals.
Among the manufactures are brass and copper work, wire for electrical uses, foundry and machine-shop products, locomotives, knit goods, tin cans and canned goods (especially vegetables).
Slate quarries and copper and tin mines were formerly valuable.
This water cannot be entirely removed by fractional distillation, and to prepare anhydrous or "absolute" alcohol the commercial product must be allowed to stand over some dehydrating agent, such as caustic lime, baryta, anhydrous copper sulphate, &c., and then distilled.
Gold has a characteristic yellow colour, which is, however, notably affected by small quantities of other metals; thus the tint is sensibly lowered by small quantities of silver, and heightened by copper.
Magnetic pyrites, copper pyrites, zinc blende and arsenical pyrites are other and less important examples, the last constituting the gold ore formerly worked in Silesia.
Gold readily alloys with silver and copper to form substances in use from remote times for money, jewelry and plate.
Other metals which find application in the metallurgy of gold by virtue of their property of extracting the gold as an alloy are lead, which combines very readily when molten, and which can afterwards be separated by cupellation, and copper, which is separated from the gold by solution in acids or by electrolysis; molten lead also extracts gold from the copper-gold alloys.