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metals

metals Sentence Examples

  • "There's a lot more metals than gold and silver," Dean said.

  • The air was tinged with the scent of burning wood and melted metals, sulfur, and the facility's damp mustiness.

  • This salt may be used for the separation of cobalt and nickel, since the latter metal does not form a similar double nitrite, but it is necessary that the alkaline earth metals should be absent, for in their presence nickel forms complex nitrites containing the alkaline earth metal and the alkali metal.

  • Imports include woven goods, metals, ironware, machinery, tea, wines and spirits, mineral oils, opium, paper, and arms and powder.

  • Leone to the west of Cagliari, and antimony and other metals near Lanusei, but in smaller quantities than in the Iglesias district, so that comparatively little mining has as yet been done there.

  • In light Kundt's name is widely known for his inquiries in anomalous dispersion, not only in liquids and vapours, but even in metals, which he obtained in very thin films by means of a laborious process of electrolytic deposition upon platinized glass.

  • Though destitute of metals Aisne furnishes abundance of freestone, gypsum and clay.

  • upon these metals.

  • He carried out a number of magnetic investigations which resulted in the discovery of many interesting phenomena, some of which have been rediscovered by others; they related among other things to the effect of mechanical strain on the magnetic properties of the magnetic metals, to the relation between the chemical composition of compound bodies and their magnetic properties, and to a curious parallelism between the laws of torsion and of magnetism.

  • On the other hand, they show faintly acid properties since the hydrogen: of the amido group can be replaced by metals to give such compounds as mercury acetamide (CH 3 CONH) 2 Hg.

  • It does not react with the alkali metals, but combines with magnesium at a low red heat to form a boride, and with other metals at more or less elevated temperatures.

  • The principal items of export are wool, skins, tallow, frozen mutton, chilled beef, preserved meats, butter and other articles of pastoral produce, timber, wheat, flour and fruits, gold, silver, lead, copper, tin and other metals.

  • The imports are chiefly textiles, metals and hardware, and gin.

  • Rajputana produces a variety of metals.

  • The principal manufactures are cotton and woollen goods, carvings in ivory and working in metals, &c., all of which handicrafts are chiefly carried on in the eastern states.

  • The cadmium molecule, as shown by determinations of the density of its vapour, is monatomic. The metal unites with the majority of the heavy metals to form alloys; some of these, the so-called fusible alloys, find a useful application from the fact that they possess a low melting-point.

  • (exclusive of Precious Metals).i Year.

  • The most important imports are minerals, including coal and metals (both in pig and wrought); silks, raw, spun and woven; stone, potters earths, earthenware and glass; corn, flour and farinaceous products; cotton, raw, spun and woven; and live stock.

  • The superiority of animals to plants and metals in the possession of special organs of sense is connected with the greater complexity and heterogeneity of their structure.

  • The astrological belief that plants, animals and minerals are under the influence of the planets is shown in the older names of some of the metals, e.g.

  • The green plant prefers as a rule nitrates of various metals, such as calcium, magnesium or potassium.

  • Long ago the view that this gas might be the source of the combined nitrogen found in different forms within the plant, was critically examined, particularly by Boussingault, and later by Lawes and Gilbert and by Pugh, and it was ascertained to be erroneous, the plants only taking nitrogen into their substance when it is presented to their roots in the form of nitrates of various metals, or compounds of ammonia.

  • Davy showed that they were oxides of various metals.

  • The metals comprising this group are never found in the uncombined condition, but occur most often in the form of carbonates and sulphates; they form oxides of the type RO, and in the case of calcium, strontium and barium, of the type R02.

  • The salts of all the metals of this group usually crystallize well, the chlorides and nitrates dissolve readily in water, whilst the carbonates, phosphates and sulphates are either very sparingly soluble or are insoluble in water.

  • The hydrogen of the hydroxyl group in phenol can be replaced by metals, by alkyl groups and by acid radicals.

  • The metallic derivatives (phenolates, phenates or carbolates) of the alkali metals are obtained by dissolving phenol in a solution of a caustic alkali, in the absence of air.

  • It combines with many metals to form sulphides, and also decomposes many metallic salts with consequent production of sulphides, a property which renders it extremely useful in chemical analysis.

  • It may also be obtained by heating carbon, sulphur and many metals with concentrated sulphuric acid: C + 2H 2 SO 4 = 2SO 2 }- CO 2 + 2H 2 O; S + 2H 2 SO 4 = 3S0 2 + 2H 2 0; Cu + 2H 2 SO 4 = SO 2 -fCuSO 4 + 2H 2 0; and by decomposing a sulphite, a thiosulphate or a thionic acid with a dilute mineral acid.

  • The sulphites are prepared by the action of sulphur dioxide on the oxides, hydroxides or carbonates of the metals, or by processes of precipitation.

  • - The sources of all sulphur preparations used in medicine (except calx sulphurata) are native virgin sulphur and the sulphides of metals.

  • Notwithstanding the wealth of the country in minerals and metals of all kinds, and the endeavours made by government to encourage mining, including the imposition of protective Mining tariffs even against Finland (in 1885), this and the related and re- industries are still at a low stage of development.

  • The imports of foreign metals in the rough and of coal are steadily increasing, while the exports, never otherwise than insignificant, show no advance.

  • The Ural industry is the older, and is still conducted on primitive methods, wood being largely used for fuel, and the ore and metals being transported by water down the Kama and other rivers.

  • By 1882 they had produced $60,000,000 of precious metals.

  • By far the greater portion of these metals came from the southern part of the state.

  • plastic objects, carved in stone or ivory, cast or beaten in metals (gold, silver, copper and bronze), or modelled in clay, faience, paste, &c. Very little trace has yet been found of large free sculpture, but many examples exist of sculptors' smaller work.

  • Vases of all kinds, carved in marble or other stones, cast or beaten in metals or fashioned in clay, the latter in enormous number and variety, richly ornamented with coloured schemes, and sometimes bearing moulded decoration.

  • Many salts of the acid are known and, with the exception of those of the alkali metals, they are difficultly soluble in water.

  • The citrates are a numerous class of salts, the most soluble of which are those of the alkaline metals; the citrates of the alkaline earth metals are insoluble.

  • No metals have ever been discovered in Florida.

  • In the narrow sense of the word, alchemy is the pretended art of making gold and silver, or transmuting the base metals into the noble ones.

  • Some are in Greek and demotic, and one, of peculiar interest from the chemical point of view, gives a number of receipts, in Greek, for the manipulation of base metals to form alloys which simulate gold and are intended to be used in the manufacture of imitation jewellery.

  • The author of these receipts is not under any delusion that he is transmuting metals; the MS. is merely a workshop manual in which are described processes in daily use for preparing metals for false jewellery, but it argues considerable knowledge of methods of making alloys and colouring metals.

  • Thus, in the treatise known as Physica et Mystica and falsely ascribed to Democritus (such false attributions are a constant feature of the literature of alchemy), various receipts are given for colouring and gilding metals, but the conception of transmutation does not occur.

  • Later, however, as in the Commentary on this work written by Synesius to Dioscorus, priest of Serapis at Alexandria, which probably dates from the end of the 4th century, a changed attitude becomes apparent; the more practical parts of the receipts are obscured or omitted, and the processes for preparing alloys and colouring metals, described in the older treatise, are by a mystical interpretation represented as resulting in real transmutation.

  • The conception of man, the microcosm, containing in himself all the parts of the universe or macrocosm, is also Babylonian, as again probably is the famous identification of the metals with the planets.

  • Of the first group the most interesting and possibly the oldest is the Book of Crates; it is remarkable for containing some of the signs used for the metals by the Greek alchemists, and for giving figures of four pieces of apparatus which closely resemble those depicted in Greek MSS., the former being never, and the latter rarely, found in other Arabic MSS.

  • The fundamental theory of the transmutation of metals is to be found in the Greek alchemists, although in details it was modified and elaborated by the Arabs and the Latin alchemists.

  • But the most eager search of Arabian chemistry was the transmutation of metals, and the elixir of immortal health: the reason and the fortunes of thousands were evaporated in the crucibles of alchemy, and the consummation of the great work was promoted by the worthy aid of mystery, fable and superstition."

  • This is briefly the doctrine that the metals are composed of mercury and sulphur, which persisted in one form or another down to the 17th century.

  • Later, as in the works attributed to Basil Valentine, sulphur, mercury and salt are held to be the constituents of the metals.

  • But even among the late Arabian alchemists it was doubted whether the resources of the art were adequate to the task; and in the West, Vincent of Beauvais remarks that success had not been achieved in making artificial metals identical with the natural ones.

  • The metals he produced are said to have proved genuine on assay; when, however, in the following year he was challenged to repeat the experiments he was unable to do so and committed suicide.

  • Like most of the other metals of the group, it absorbs gases.

  • The chief imports are cotton piece goods, cotton twist, salt, sugar, provisions, railway materials, raw cotton, metals, coal, tobacco, spices and kerosene oil.

  • This section treats of the qualitative detection and separation of the metals, and the commoner methods employed in quantitative analysis.

  • The search for this essence subsequently resolved itself into the desire to effect the transmutation of metals, more especially the base metals, into silver and gold.

  • In the view of some alchemists, the ultimate principles of matter were Aristotle's four elements; the proximate constituents were a " sulphur " and a " mercury," the father and mother of the metals; gold was supposed to have attained to the perfection of its nature by passing in succession through the forms of lead, brass and silver; gold and silver were held to contain very pure red sulphur and white quicksilver, whereas in the other metals these materials were coarser and of a different colour.

  • 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.

  • Notwithstanding the false idea which prompted the researches of the alchemists, many advances were made in descriptive chemistry, the metals and their salts receiving much attention, and several of our important acids being discovered.

  • Metals on calcination gave calces from which the metals could.

  • The objections of the antiphlogistonists, such as the fact that calces weigh more than the original metals instead of less as the theory suggests, were answered by postulating that phlogiston was a principle of levity, or even completely ignored as an accident, the change of qualities being regarded as the only matter of importance.

  • 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,.

  • elements received symbols composed of circles, arcs of circles, and lines, while certain class symbols, such as1W for metals, - - foracids, for alkalies, for salts, U for calces, &c., were used.

  • (the " simple acidifiable bases " of Lavoisier), and circles enclosing the initial letters of their names for the metals.

  • Gerhardt found that reactions could be best followed if one assumed the molecular weight of an element or compound to be that weight which occupied the same volume as two unit weights of hydrogen, and this assumption led him to double the equivalents accepted by Gmelin, making H= 1, 0 =16, and C = 12, thereby agreeing with Berzelius, and also to halve the values given by Berzelius to many metals.

  • The elements are usually divided into two classes, the metallic and the non-metallic elements; the following are classed as non-metals, and the remainder as metals: Of these hydrogen, chlorine, fluorine, oxygen, nitrogen, argon, neon, krypton, xenon and helium are gases, bromine is a liquid, and the remainder are solids.

  • All the metals are solids at ordinary temperatures with the exception of mercury, which is liquid.

  • eilos, like), strictly belongs to certain elements which do not possess the properties of the true metals, although they more closely resemble them than the non-metals in many respects; thus, selenium and tellurium, which are closely allied to sulphur in their chemical properties, although bad conductors of heat and electricity, exhibit metallic lustre and have relatively high specific gravities.

  • But the difference between these two classes of elements is one of degree only, and they gradually merge into each other; moreover the electric relations of elements are not absolute, but vary according to the state of combination in which they exist, so that it is just as impossible to divide the elements into two classes according to this property as it is to separate them into two distinct classes of metals and non-metals.

  • The metals may be arranged in a series according to their power of displacing one another in salt solutions, thus Cs, Rb, K, Na, Mg, Al, Mn, Zn, Cd, Tl, Fe, Co, Ni, Sn, Pb, (H), Sb, Bi, As, Cu, Hg, Ag, Pd, Pt, Au.

  • An acid (q.v.) is a compound of hydrogen, which element can be replaced by metals, the hydrogen being liberated, giving substances named salts.

  • Group I.: the alkali metals Li, Na, K, Rb, Cs, and also Ag, monovalent; Cu, monovalent and divalent; Au, monovalent and trivalent.

  • Group II.: the alkaline earth metals Ca, Sr, Ba, and also Be (GI), Mg, Zn, Cd, divalent; Hg, monovalent and divalent.

  • The action of these acids on many metals was also studied; Glauber obtained zinc, stannic, arsenious and cuprous chlorides by dissolving the metals in hydrochloric acid, compounds hitherto obtained by heating the metals with corrosive sublimate, and consequently supposed to contain mercury.

  • 1 The metals of the alkaline-earths were somewhat neglected; we find Georg Agricola considering gypsum (calcium sulphate) as a compound of lime, while calcium nitrate and chloride became known at about the beginning of the 17th century.

  • Vauquelin in 1797, and Klaproth's investigation of tellurium in 1798, the next important series of observations was concerned with platinum and the allied metals.

  • The great number and striking character of the compounds of this group of metals have formed the subject of many investigations, and already there is a most voluminous literature.

  • Foerster and by Pullinger; the phosphoplatinic compounds formed primarily from platinum and phosphorus pentachloride; and also the " ammino " compounds, formed by the union of ammonia with the chloride, &c., of these metals, which have been studied by many chemists, especially S.

  • Considerable uncertainty existed as to the atomic weights of these metals, the values obtained by Berzelius being doubtful.

  • Berzelius's investigation of the action of the electric current on salts clearly demonstrated the invaluable assistance that electrolysis could render to the isolator of elements; and the adoption of this method by Sir Humphry Davy for the analysis of the hydrates of the metals of the alkalis and alkaline earths, and the results which he thus achieved, established its potency.

  • Here he met with greater difficulty, and it is to be questioned whether he obtained any of these metals even in an approximately pure form (see Electrometallurgy).

  • 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.

  • Within two years of the invention the authors announced the discovery of two metals, rubidium and caesium, closely allied to sodium, potassium and lithium in properties, in the mineral lepidolite and in the Diirkheim mineral water.

  • BdXXo, a green bud, on account of a brilliant green line in its spectrum) in the selenious mud of the sulphuric acid manufacture; the chemical affinities of this element, on the one hand approximating to the metals of the alkalis, and on the other hand to lead, were mainly established by C. A.

  • Of other metals first detected by the spectroscope mention is to be made of indium, determiped by F.

  • Cleve proposed to divide the " rare earth " metals into two groups, (1) " perfectly characterized "; (2) " not yet thoroughly characterized."

  • Of recent years the introduction of various organic compounds as precipitants or reagents has reduced the labour of the process; and advantage has also been taken of the fairly complex double salts which these metals form with compounds.

  • These crude earths, yttria and ceria, have supplied most if not all of the " rare earth " metals.

  • Taking as a basis the nature of the source of compounds, he framed three classes: " mineral," comprising the metals, minerals, earths and stones; " vegetable," comprising plants, resins, gums, juices, &c.; and " animal," comprising animals, their different parts and excreta.

  • Bergman laid the foundations of systematic qualitative analysis, and devised methods by which the metals may be separated into groups according to their behaviour with certain reagents.

  • He applied himself more particularly to the oxygen compounds, and determined with a fair degree of accuracy the ratio of carbon to oxygen in carbon dioxide, but his values for the ratio of hydrogen to oxygen in water, and of phosphorus to oxygen in phosphoric acid, are only approximate; he introduced no new methods either for the estimation or separation of the metals.

  • The quantitative precipitation of metals by the electric current, although known to Michael Faraday, was not applied to analytical chemistry until O.

  • This has led to the estimation of sugar by means of the polarimeter, and of the calorific power of fuels, and the valuation of ores and metals, of coal-tar dyes, and almost all trade products.

  • The limits of space prevent any systematic account of the separation of the rare metals, the alkaloids, and other classes of organic compounds, but sources where these matters may be found are given in the list of references.

  • Oxygen, recognized by its power of igniting a glowing splinter, results from the decomposition of oxides of the noble metals, peroxides, chlorates, nitrates and other highly oxygenized salts.

  • (a) The substance may fuse and be absorbed by the charcoal; this indicates more particularly the alkaline metals.

  • Certain substances, such as the precious metals, are quite insoluble in the bead, but float about in it.

  • The procedure for the detection of metals in solution consists of first separating them into groups and then examining each group separately.

  • If, however, phosphoric acid is present in the original substance,we may here obtain a precipitate of the phosphates of the remaining metals, together with aluminium, chromium and ferric hydrates.

  • The phosphates of aluminium, chromium and iron are precipitated, and the solution contains the same metals as if phosphoric acid had been absent.

  • The remaining metals are tested for separately.

  • Details will be found in the articles on particular metals.

  • Lead and manganese are partially separated as peroxides, but the remaining metals are not deposited from acid solutions.

  • It is therefore necessary that the solution should be free from metals which may vitiate the results, or special precautions taken by which the impurities are rendered harmless.

  • Nilson and Pettersson's observations on beryllium and germanium have shown that the atomic heats of these metals increase with rise of temperature, finally becoming constant with a value 5.6.

  • Other metals were tested in order to determine if their atomic heats approximated to this value at low temperatures, but with negative results.

  • With acid substances, the combination with " colourless " metals, i.e.

  • metals producing colourless salts with acids, is attended by colour changes contrary to those given above, auxochromic combination being accompanied by a deepening, and chromophoric by a lessening of the tint.

  • This fact finds a parallel in the atomic weights of these metals.

  • Roscoe and Schorlemmer, Inorganic Chemistry (3rd ed., Non-metals, 1905; Metals, 1907); R.

  • 60 An interesting discovery of the late period in Upper Egypt, that of images and other temple objects of precious metals, was also made at Dendera by the diggers for natron (sebakh) and recovered by the Service des Antiquites for the Cairo Museum.61 Outside Egypt proper the work of editing and publishing all the Egyptian inscriptions of Sinai has been begun by Dr. Gardiner and Mr. Peet.62 A worthy completion of the record is the wonderful exhibition of all the finest examples of Egyptian art in Britain outside the British and Ashmolean Museums, held by the Burlington Fine Arts' Club in London in the summer of 1921.63

  • Gold had fallen still further from the diffusion of the Persian treasure, and Alexander struck in both metals on the Attic standard, leaving their relation to adjust itself by the state of the market.

  • Mining is carried on only to a small extent for arsenic, although there are traces of former more extensive workings for other metals.

  • Traditions of gold and silver, dating from the time of the Spanish conquest, still endure, but these metals are in fact extremely rare.

  • Mining for the precious metals ceased at a very early date, after rich discoveries were made on the continent.

  • The proportion of imports taken from the United States is greatest in foodstuffs, metals and metal manufactures, timber and furniture, mineral oils and lard.

  • It combines directly with lithium, calcium and magnesium when heated, whilst nitrides of the rare earth metals are also produced when their oxides are mixed with magnesium and heated in a current of nitrogen (C. Matignon, Comptes rendus, 1900, 131, p. 837).

  • It converts many metallic oxides into mixtures of nitrates and nitrites, and attacks many metals, forming nitrates and being itself reduced to nitric oxide.

  • The imports are woollen and cotton piece-goods, metals and petroleum.

  • ERBIUM (symbol, Er; atomic weight, 165-166), one of the metals of the rare earths.

  • The rare earth metals are found in the minerals gadolinite, samarskite, fergusonite, euxenite and cerite.

  • - These are the materials which are utilized by the vegetable plankton in the synthesis of living material: they are water, carbonic acid, nitrates and nitrites of calcium, magnesium and other earthy and alkaline metals, phosphates, silica, traces of salts containing iron, sulphur, potassium and a few other elements.

  • 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.

  • This observation showed that nascent hydrogen was not, as had been supposed, the primary cause of the separation of metals from their solutions, but that the action consisted in a direct decomposition into metal and acid.

  • In 1807 he decomposed potash and soda, previously considered to be elements, by passing the current from a powerful battery through the moistened solids, and thus isolated the metals potassium and sodium.

  • The salt must therefore be derived from an acid, chloroplatinic acid, H 2 PtC1 6, and have the formula Na 2 PtC1 6, the ions being Na and PtCls", for if it were a double salt it would decompose as a mixture of sodium chloride and platinum chloride and both metals would go to the cathode.

  • The mean values of the relative coagulative powers of sulphates of mono-, di-, and tri-valent metals have been shown experimentally to be approximately in the ratios 1 :35:1023.

  • When two metallic conductors are placed in an electrolyte, a current will flow through a wire connecting them provided that a difference of any kind exists between the two conductors in the nature either of the metals or of the portions of the electrolyte which surround them.

  • A current can be obtained by the combination of two metals in the same electrolyte, of two metals in different electrolytes, of the same metal in different electrolytes, or of the same metal in solutions of the same electrolyte at different concentrations.

  • In ordinary cells the difference is secured by using two dissimilar metals, but an electromotive force exists if two plates of the same metal are placed in solutions of different substances, or of the same substance at different concentrations.

  • It is now evident that the electromotive force of an ordinary chemical cell such as that of Daniell depends on the concentration of the solutions as well as on the nature of the metals.

  • If secondary effects are eliminated, the deposition of metals also is a reversible process; the decomposition voltage is equal to the electromotive force which the metal itself gives when going into solution.

  • Many experiments have been made with a view of separating the two potential-differences which must exist in any cell made of two metals and a liquid, and of determining each one individually.

  • On the other hand, it is commonly thought that the single potentialdifferences at the surface of metals and electrolytes have been determined by methods based on the use of the capillary electrometer and on others depending on what is called a dropping electrode, that is, mercury dropping rapidly into an electrolyte and forming a cell with the mercury at rest in the bottom of the vessel.

  • The contact differences of potential at the interfaces of metals and electrolytes have been co-ordinated by Nernst with those at the surfaces of separation between different liquids.

  • In metals the electrons can slip from one atom to the next, since a current can pass without chemical action.

  • ELECTROPLATING, the art of depositing metals by the electric current.

  • The vats for depositing may be of enamelled iron, slate, glazed earthenware, glass, lead-lined wood, &c. The current densities and potential differences frequently used for some of the commoner metals are given in the following table, taken from M ` Millan's Treatise on Electrometallurgy.

  • By varying this process, designs in metals of different colours may readily be obtained.

  • Other alloys may be produced, such as bronze, or German silver, by selecting solutions (usually cyanides) from which the current is able to deposit the constituent metals simultaneously.

  • Pliny treats of these two metals as plumbum nigrum and plumbum album respectively, which seems to show that at his time they were looked upon as being only two varieties of the same species.

  • Lead unites readily with almost all other metals; hence, and on account of its being used for the extraction of (for instance) silver, its alchemistic name of saturnus.

  • "Pewter" (q.v.) may be said to be substantially an alloy of the same two metals, but small quantities of copper, antimony and zinc are frequently added.

  • Practically the metals iron, nickel and cobalt, and some of their alloys and compounds constitute a class by themselves and are called ferromagnetic substances.

  • In the case of the ferromagnetic metals and some of their alloys and compounds, the permeability has generally a much higher value.

  • Fleming, Magnets and Electric Currents, p. 193) are shown three very different types of hysteresis curves, characteristic of the special qualities of the metals from which they were respectively obtained.

  • The value of the constant / 7 ranges in different metals from about o ooI to 0.04; in soft iron and steel it is said to be generally not far from 0.002.

  • These are to be regarded merely as typical specimens, for the details of a curve depend largely upon the physical condition and purity of the material; but they show at a glance how far the several metals differ from and resemble one another as regards their magnetic properties.

  • The annexed table gives the saturation values of I for the particular metals examined by Ewing and Low: Wrought iron .

  • In hardened iron and steel the effect can scarcely be detected, and in weak fields these metals exhibit no magnetic hysteresis of any kind.

  • Honda, measured the changes of length of various metals shaped in the form of ovoids instead of cylindrical rods, and determined the magnetization curves for the same specimens; a higher degree of accuracy was thus attained, and satisfactory data were provided for testing theories.

  • Nagaoka and Honda, who employed a fluid dilatometer, found that the volume of several specimens of iron, steel and nickel was always slightly increased, no diminution being indicated in low fields; cobalt, on the other hand, was diminished in volume, and the amount of the change, though still very small, was greater than that shown by the other metals.

  • Knott, who made an exhaustive series of experiments upon various metals in the form of tubes, concluded that in iron there was always a slight increase of volume, and in nickel and cobalt a slight decrease.

  • It is uncertain how far these various results are dependent upon the physical condition of the metals.

  • So, too, the Villari reversals in iron and cobalt might have been predicted - as indeed that in cobalt actually was - from a knowledge of the changes of length which those metals exhibit when magnetized.

  • It would hardly be safe to generalize from these observations; the effects may possibly be dependent upon the physical condition of the metals.

  • For each of the metals tabulated in the first column all the effects hitherto observed have the same sign; there is no single instance in which some are positive and others negative.

  • The magnetometric method was employed, and the metals, in the form of ovoids, were heated by a specially designed burner, fed with gas and air under pressure, which directed 90 fine jets of flame upon the asbestos covering the ovoid.

  • In the case of all the metals tested a small but measurable trace of magnetization remained after the so-called critical temperature had been exceeded; this decreased very slightly up to the highest temperature reached (1200°) without undergoing any such variation as had been suspected by Morris.

  • Honda and Shimizu have made similar experiments at the temperature of liquid air, employing a much wider range of magnetizing forces (up to about 700 C.G.S.) and testing a greater variety of metals.

  • They found that the permeability of Swedish iron, tungsten-steel and nickel, when the metals were cooled to - 186°, was diminished in weak fields but increased in strong ones, the field in which the effect of cooling changed its sign being 115 for iron and steel and 580 for nickel.

  • It may be remarked that, whereas Fleming and Dewar employed the ballistic method, their specimens having the form of rings, Honda and Shimizu worked magnetometrically with metals shaped as ovoids.

  • magnetized metals when cooled to the temperature of liquid air.

  • became definite and cyclic. When the permanent magnetic condition had been thus established, it was found that in the case of all the metals, except the two alloys containing large percentages of nickel, the magnetic moment was temporarily increased by cooling to - 186°.

  • An alloy containing about 3 parts of iron and I of nickel - both strongly magnetic metals - is under ordinary conditions practically non-magnetizable (1 1=1'4 for any value of H).

  • All the metals were annealed.

  • 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.

  • So far, the best results have been attained with aluminium, and the permeability was greatest when the percentages of manganese and aluminium were approximately proportional to the atomic weights of the two metals.

  • Next to aluminium, tin was found to be the most effective of the metals enumerated above.

  • Manganese, though belonging (with chromium) to the iron group of metals, is commonly classed as a paramagnetic, its susceptibility being very small in comparison with that of the recognized ferromagnetics; but it is remarkable that its atomic susceptibility in solutions of its salts is even greater than that of iron.

  • Now iron, nickel and cobalt all lose their magnetic quality when heated above certain critical temperatures which vary greatly for the three metals, and it was suspected by Faraday 3 as early as 1845 that manganese might really be a ferromagnetic metal having a critical temperature much below the ordinary temperature of the air.

  • If this view is correct, it may also be possible to prepare magnetic alloys of chromium, the only other paramagnetic metals of the iron group.

  • The following values of K for different metals are given by E.

  • Thomson (Lord Kelvin), who in 1856 announced that magnetization rendered iron and steel positive to the unmagnetized metals.'

  • [[[Feebly Susceptible Substances]] different specimens were tested, all of which became, like iron, thermo-electrically positive to the unmagnetized metals.

  • Sitz., 1897, 106, II.a, p. 623, and 1898, 107, II.a, p. 5) the atomic susceptibilities k of the metals nickel, chromium, iron, cobalt and manganese in solutions of their salts are as follows: - Fe(i) is iron contained in FeC1 2 and Fe(2) iron contained in Fe2(NOs)s.

  • Meyer thinks that the susceptibilities of the metals praseodymium, neodymium, ytterbium, samarium, gadolinium, and erbium, when obtained in a pure form, will be found to equal or even exceed those of the well-known ferromagnetic metals.

  • The process of electric conduction in metals consists in the movement of detached electrons, and many other phenomena, both electrical and thermal, can be more or less completely explained by their agency.

  • Rowland,' whose careful experiments led to general recognition of the fact previously ignored by nearly all investigators, that magnetic susceptibility and permeability are by no means constants (at least in the case of the ferromagnetic metals) but functions of the magnetizing force.

  • Induction in Iron and other Metals (3rd ed., London, 2900); Thomson, Recent Researches in Electricity and Magnetism (Oxford, 2893); Elements of Mathematical Theory of Electricity and Magnetism 3rd ed., Cambridge, 1904); H.

  • Besides wool, leading imports are jute, cotton, flax, timber, petroleum, coal, pitch, wine, cereals, oil-seeds and oil-cake, nitrate of soda and other chemical products, and metals.

  • Debray (1827-1888) he worked at the platinum metals, his object being on the one hand to prepare them pure, and on the other to find a suitable metal for the standard metre for the International Metric Commission then sitting at Paris.

  • is the sign of an alkali metal (potassium, sodium, rubidium, caesium), silver or ammonium, and M 111 denotes one of the trivalent metals, aluminium, chromium or ferric iron.

  • 2 The " old metals " consist of old iron, brass, &c., derived from railway material, machinery, &c., all imported, and should not be considered a Brazilian product.

  • It is worthy of observation, that Brazil was the first colony founded in America upon an agricultural principle, for until then the precious metals were the exclusive attraction.

  • who, first searching whether their new country were rich in metals, soon began adventurous raids into the interior, making excursions also against the remote Indian tribes with a view to obtaining slaves, and from the year 1629 onwards repeatedly attacked the Indian reductions of the Jesuits in Paraguay, although both provinces were then nominally subject to the crown of Spain.

  • There is trade in agricultural produce, wine, metals, &c. The canal from the Rhone to the Rhine passes under the citadel by way of a tunnel, and the port of Besancon has considerable trade in coal, sand, &c.

  • There are extensive copper and goldyielding areas, and in some districts these metals are mined.

  • In chemistry he made a speciality of the platinum metals.

  • Platinum itself he discovered how to work on a practical scale, and he is said to have made a fortune from the secret, which, however, he disclosed in a posthumous paper (1829); and he was the first to detect the metals palladium (1804)(1804) and rhodium (1805) in crude platinum.

  • He saw that the amount of money in circulation did not constitute the wealth of the community, and that the prohibition of the export of the precious metals was rendered inoperative by the necessities of trade.

  • The mother liquor includes generally more or less of nickel, cobalt, zinc and other heavy metals, which, as Wailer showed, can be removed as insoluble sulphides by the addition of ammonium sulphide; uranium, under the circumstances, is not precipitated by this reagent.

  • Of minerals containing this element mention may be made of cassiterite or tinstone, Sn02, tin pyrites, Cu 4 SnS 4 + (Fe,Zn) 2 SnS 4; the metal also occurs in some epidotes, and in company with columbium, tantalum and other metals.

  • There are coal-mines at Nong-Son, near Tourane, and gold, silver, lead, iron and other metals occur in the mountains.

  • 32 negro slaves were introduced; but less attention was given by the Spaniards to this region than to other parts of Spanish America, which were known to be rich in the precious metals.

  • Special methods of mining are dealt with in the separate articles on Coal, Gold, and other minerals and metals.

  • Other metals, such as manganese, copper, nickel, may show their presence by characteristic colours.

  • On the other hand, in the case of less regular deposits, including most metalliferous veins, and especially those of the precious metals, the uncertainty is often very great, and it is sometimes necessary to work on a small scale for months before any considerable expenditure of money is justified.

  • 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.

  • It did excellent service in the hands of Graham for the extraction of gases occluded in metals.

  • The theory most widely accepted at present is that glass is a quickly solidified solution, in which silica, silicates, borates, phosphates and aluminates may be either solvents or solutes, and metallic oxides and metals may be held either in solution or in suspension.

  • C. Maxwell Garnett, who has studied the optical properties of these glasses, has suggested that the changes in colour correspond with changes effected in the structure of the metals as they pass gradually from solution in the glass to a state of crystallization.

  • It is found in the form of oxide (silica), either anhydrous or hydrated as quartz, flint, sand, chalcedony, tridymite, opal, &c., but occurs chiefly in the form of silicates of aluminium, magnesium, iron, and the alkali and alkaline earth metals, forming the chief constituent of various clays, soils and rocks.

  • The older methods used for the preparation of the amorphous form, namely the decomposition of silicon halides or silicofluorides by the alkali metals, or of silica by magnesium, do not give good results, since' the silicon obtained is always contaminated with various impurities, but a pure variety may be prepared according to E.

  • It combines directly with many metals on heating, whilst others merely dissolve it.

  • When heated with the alkali and alkaline earth metals it yields silicon and the corresponding metallic chlorides.

  • 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.

  • The acid carbonates of the alkali metals can be prepared by saturating an aqueous solution of the alkaline hydroxide with carbon dioxide, M OH+ C02= Mhco 3, and from these acid salts the normal salts may be obtained by gentle heating, carbon dioxide and water being produced at the same time, 2Mhco 3 = M2C03+H02+C02.

  • Most other carbonates are formed by precipitation of salts of the metals by means of alkaline carbonates.

  • All carbonates, except those of the alkali metals and of thallium, are insoluble in water; and the majority decompose when heated strongly, carbon dioxide being liberated and a residue of an oxide of the metal left.

  • The individual carbonates are described under the various metals.

  • In modern chemistry, however, the metals are a division of the elements, the members of which may or may not possess all these characters.

  • This definition, however, is highly artificial and objectionable on principle, because when we speak of metals we think, not of their chemical relations, but of a certain sum of mechanical and physical properties which unites them all into one natural family.

  • All metals, when exposed in an inert atmosphere to a sufficient temperature, assume the form of liquids, which all present the following characteristic properties.

  • The liquid metals, when cooled down sufficiently, some at lower, others at higher, temperatures freeze into compact solids, endowed with the (relative) non-transparency and the lustre of their liquids.

  • These frozen metals in general form compact masses consisting of aggregates of crystals belonging to the regular or rhombic or (more rarely) the quadratic system.

  • To this remarkable combination of properties more than to anything else the ordinary metals owe their wide application in the mechanical arts.

  • In former times a high specific gravity used to be quoted as one of the characters of the genus; but this no longer holds, since we now know a series of metals lighter than water.

  • This, in the case of even the solid metals, is perhaps only a very low degree of transparency.

  • Most (perhaps all) metals are capable of crystallization.

  • Perhaps all metals are crystalline, only the degree of visibility of the crystalline arrangement is very different in different metals, and even in the same metal varies according to the slowness of solidification and other circumstances.

  • appears to be owing chiefly to the fact that, while the latter crystallize in the regular system, metals of Class I.

  • The crystalline structure which exists on both sides becomes visible only in the metals of the first class, and only there manifests itself as brittleness.

  • Closely related to the structure of metals is their degree of "plasticity" (susceptibility of being constrained into new forms without breach of continuity).

  • The quality of plasticity is developed to very different degrees in different metals, and even in the same species it depends on temperature, and may be modified by mechanical or physical operations.

  • Pure iron, copper, silver and other metals are easily drawn into wire, or rolled into sheet, or flattened under the hammer.

  • But all these operations render the metals harder, and detract from their plasticity.

  • Tresca show that the plasticity of certain metals at least goes considerably farther than had before been supposed.

  • He operated with lead, copper, silver, iron and some other metals.

  • Of the better known metals potassium and sodium are the softest; they can be kneaded between the fingers like wax.

  • After these follow first thallium and then lead, the latter being the softest of the metals used in the arts.

  • As liquidity might be looked upon as the ne plus ultra of softness, this is the right place for stating that, while most metals, when heated up to their melting points, pass pretty abruptly from the solid to the liquid state, platinum and iron first assume, and throughout a long range of temperatures retain, a condition of viscous semi-solidity which enables two pieces of them to be "welded" together by pressure into one continuous mass.

  • According to Prechtl, the ordinary metals, in regard to the degree of facility or perfection with which they can be hammered flat on the anvil, rolled out into sheet, or drawn into wire, form the following descending series: Hammering.

  • All metals are elastic to this extent that a change of form, brought about by stresses not exceeding certain limit values, will disappear on the stress being removed.

  • This varies in metals from 594 (lithium) to 22.48 (osmium), and in one and the same species is a function of temperature and of previous physical and mechanical treatment.

  • The following table gives the specific gravities of many metals.

  • Thermal Properties.-The specific heats of most metals have been determined.

  • The coefficient of expansion is constant for such metals only as crystallize in the regular system; the others expand differently in the directions of the different axes.

  • To eliminate this source of uncertainty these metals were employed as compressed powders.

  • For practical purposes the volatility of metals may be stated as follows: i.

  • Distillable at red heats: cadmium, alkali metals, zinc, magnesium.

  • The following table gives the electric conductivities of a number of metals as determined by Matthiesen, and the relative internal thermal conductivities of (nominally) the same metals as determined by Wiedemann and Franz, with rods about 5 mm.

  • - Iron, nickel and cobalt are the only metals which are attracted by the magnet and can become magnets themselves.

  • Metals may unite chemically both with metals and with non-metals.

  • Metallic Substances Produced by the Union of Metals with Small Proportions of Non-Metallic Elements.

  • Hydrogen, as was shown by Graham, is capable of uniting with or being occluded by certain metals, notably with palladium (q.v.), into metal-like compounds.

  • Mercury and copper and some other metals are capable of dissolving their own oxides.

  • But the presence of moderate proportions of cuprous oxide has been found to correct the evil influence of small contaminations by arsenic, antimony, lead and other foreign metals.

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