Metal Sentence Examples
The porch posts were black metal with a filigree design.
After that, metal was too important to waste.
She returned with two raw steaks on a metal platter.
They called him metal man.
The heavy metal box grated towards her.Advertisement
She went to a cabinet and returned with a metal tray and a knife.
You're metalman29—a metal collector.
Her fingers worked across the hard metal seat and under.
Brady entered the code from his micro onto the keypad beside the metal door in front of him.
Three stories tall, the old mill stood picturesquely at the edge of the river, an old metal one-lane bridge at one side beckoned travelers to visit the lush pastures on the other side.Advertisement
The scent of charred flesh and metal still lingered, and Lana covered her mouth and nose with her hand as she started forward again.
Maybe 'metalman' is some sheet metal worker or some heavy metal rocker.
It was only moments later when his fears were realized by the gnashing, booming, ripping sound of metal on rock, echoing across the valley like a clap of thunder, repeating and repeating, as if car after car had met a similar fate, further and further away.
She opened the door to her tiny room, taking in the two twin beds with sagging metal frames.
Her fingers grazed the cold metal, and she stretched towards it.Advertisement
A man opened the metal door and another entered with a tray holding two large, silver goblets.
In the middle, Elisabeth sat in a metal chair, barely conscious.
He led her down a set of stairs and through a thick metal door at the bottom.
As if on cue, an old car with more rust than clear metal chugged to a stop at the dollar store.
The screech of metal on metal drove her to cover her ears as she moved farther away.Advertisement
The fed building smoldered before him, the scent of metal and burning plastic thick in the air.
The flash of metal drew her attention, and she raised her eyes as he trailed the dagger down his forearm.
Dumas (Ann., 1860, 113, p. 32), by converting the trioxide into the metal, obtained the value 95.65.
On the analogy between this case and that of the interface between two solutions, Nernst has arrived at similar logarithmic expressions for the difference of potential, which becomes proportional to log (P 1 /P 2) where P2 is taken to mean the osmotic pressure of the cations in the solution, and P i the osmotic pressure of the cations in the substance of the metal itself.
It is usually prepared by dissolving the metal in aqua regia.Advertisement
Zinc oxide, ZnO, is maufactured for paint by two processes - directly from the ore mixed with coal by volatilization on a grate, as in the Wetherill oxide process, and by oxidizing the vapour given off by a boiling bath of zinc metal.
This at least is true of the oxide produced from the metal by combustion; that produced from the carbonate, if once made yellow at a red heat, retains a yellow shade permanently.
Zinc sulphate, ZnS04+7H20, or white vitriol, is prepared by dissolving the metal in dilute sulphuric acid.
In the case of acetate the precipitation is quite complete; from a sulphate or chloride solution the greater part of the metal goes into the precipitate; in the presence of a sufficiency of free HC1 the metal remains dissolved; sulphide of ammonium precipitates the metal completely, even in the presence of ammonium salts and free ammonia.
Numerous other salts of zinc, used in medicine, are of value as containing this metal.
The action was started in the cold, the alkali being slightly moistened to render it a conductor; then, as the current passed, heat was produced and the alkali fused, the metal being deposited in the liquid condition.
When used for ore smelting, the reduced metal and the accompanying slag were to be caught, after leaving the arc and while still liquid, in a hearth fired with ordinary fuel.
When the furnace with this well-known regulating device was to be used, say, for the melting of metals or other conductors of electricity, the fragments of metal were placed in the crucible and the positive electrode was brought near them.
Immediately the current passed through the solenoid it caused the iron cylinder to rise, and, by means of its supporting rod, forced the end of the balance beam upwards, so depressing the other end that the negative carbon rod was forced downwards into contact with the metal in the crucible.
The metal is very reactive chemically.
It was so light that he could see the moonlight reflected from the metal harness disks and from the eyes of the horses, who looked round in alarm at the noisy party under the shadow of the porch roof.
While geographical knowledge of the west was still scanty and the secrets of the tin-trade were still successfully guarded by the seamen of Gades and others who dealt in the metal, the Greeks knew only that tin came to them by sea from the far west, and the idea of tin-producing islands easily arose.
The Eastern railway has works at Romilly, and there are iron works at Clairvaux and wire-drawing works at Plaines; but owing to the absence of coal and iron mines, metal working is of small importance.
Beryllium to a certain extent stands alone in many of its chemical' properties, resembling to some extent the metal aluminium.
The eye-end of the tube is closed by a metal plate having a small hole at its centre near the intersection of the glass plates.
Several of his engravings are supposed to be executed on some metal less hard than copper.
The term is thus applied to a metal bar, slender in proportion to its length, used as a tie, brace or connecting shaft between different parts, of a machine.
Of the principal mosques the large Buyuk Djamia, with nine metal cupolas, has become the National Museum; the Tcherna Djamia or Black Mosque, latterly used as a prison, has been transformed into a handsome church; the Banyabashi Djamia, with its picturesque minaret, is still used by Moslem worshippers.
With regard to the imports into Russia-they consist mainly of raw materials and machinery for the manufactures, and of provisions, the principal items being raw cotton, 17% of the aggregate; machinery and metal goods, 13%; tea, 5%; mineral ores, 5%; gums and resins, 4%; wool and woollen yarns, 32%; textiles, 3%; fish, 3%; with leather and hides, chemicals, silks, wine and spirits, colours, fruits, coffee, tobacco and rice.
There was a waste of metal in these early rails owing to the excessive thickness of the vertical web, and subsequent improvements have consisted in adjusting the dimensions so as to combine strength with economy of metal, as well as in the substitution of steel for wrought iron (after the introduction of the Bessemer process) and in minute attention to the composition of the steel employed.
The keys which hold the rail in the chairs are usually of oak and are placed outside the rails; the inside position has also been employed, but has the disadvantage of detracting from the elasticity of the road since the weight of a passing train presses the rails up against a rigid mass of metal instead of against a slightly yielding block of wood.
Such metal plates, or " tie-plates," have come into considerable use also in the United States, where they are always made of rolled steel, punched with rectangular holes through which the spikes pass.
The rail-failures mentioned above also drew renewed attention to the importance of the thermal treatment of the steel from the time of melting to the last passage through the rolling mill and to the necessity of the finishing temperature being sufficiently low if the product is to be fine grained, homogeneous and tough; and to permit of this requirement being met there was a tendency to increase the thickness of the metal in the web and flanges of the rails.
The standard specification adopted by the Pennsylvania railway in 1908 provided that in rails weighing Ioo lb to the yard 41% of the metal should be in the head, 18-6% in the web, and 40-4% in the base, while for 85 lb rails 42.2% was to be in the head, 17-8% in the web and 40.0% in the base.
According to the specification for 85 lb rails adopted by the Canadian Pacific railway about the same time, 36-77% of the metal was to be in the head, 22'21% in the web and 41 02% in the base.
He now employed himself in making optical glasses, and in engraving on metal, devoting his spare time to the perusal of works on mathematics and optics.
Manufactures based on the products of mines and quarries (chemicals, glass, clay, stone and metal works) constituted about one-fifth of the whole product.
In the presidential election of 1900 the Nevada Republicans pursued a non-committal policy with regard to the silver question, declaring in favour of " the largest use of silver as a money metal in all matters compatible with the best interests of our government."
The sistrum is played also by beating it with a metal stick.
The metal may be obtained from the residues obtained in the separation of osmium from osmiridium.
Acids have practically no action on the metal, but it is soluble in solutions of the alkaline hypochlorites.
Ruthenium sulphides are obtained when the metal is warmed with pyrites and some borax, and the fused mass treated with hydrochloric acid first in the cold and then hot.
Potassium ruthenate, K2Ru04 H20, obtained by fusion of the metal with caustic potash and nitre, crystallizes in prisms which become covered with a black deposit on exposure to moist air.
Ponce's hospitable reception by the native chief, Aquebana or Guaybana, and his fairly profitable search for the precious metal led King Ferdinand in 1509 to give him an appointment as temporary governor of the island, where his companions had already established the settlement of Caparra (Pueblo Viejo, near the present San Juan).
The mines once produced 3000 tons of metal annually, copper smelting being largely carried on, but have now almost ceased working.
He established as fundamental that combustion and calcination were attended by an increase of weight, and concluded, as did Jean Rey and John Mayow in the 17th century, that the increase was due to the combination of the metal with the air.
He also showed that on heating mercury calx alone an " air " was liberated which differed from other " airs," and was slightly heavier than ordinary air; moreover, the weight of the " air " set free from a given weight of the calx was equal to the weight taken up in forming the calx from mercury, and if the calx be heated with charcoal, the metal was recovered and a gas named " fixed air," the modern carbon dioxide, was formed.
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,.
A base may be regarded as water in which part of the hydrogen is replaced by a metal, or by a radical which behaves as a metal.
An acid salt is one in which the whole amount of hydrogen has not been replaced by metal; a normal salt is one in which all the hydrogen has been replaced; and a basic salt is one in which part of the acid of the normal salt has been replaced by oxygen.
Peligot, who prepared the pure metal, that Klaproth's product was really an oxide.
In the same year as Klaproth detected uranium, he also isolated zirconia or zirconium oxide from the mineral variously known as zircon, hyacinth, jacynth and jargoon; but he failed to obtain the metal, this being first accomplished some years later by Berzelius, who decomposed the double potassium zirconium fluoride with potassium.
In the following year he announced that silica was the oxide of a hitherto unrecognized element, which he named silicium, considering it to be a metal.
Matthiessen in 1855, who obtained the metal by electrolysis and thoroughly examined it and its compounds.
If the crystal structure be regarded as composed of 0 three interpenetrating point systems, one consisting of sulphur atoms, the second of four times as many oxygen atoms, and the third of twice as many potassium atoms, the systems being so arranged that the sulphur system is always centrally situated with respect to the other two, and the potassium system so that it would affect the vertical axis, then it is obvious that the replacement of potassium by an element of greater atomic weight would specially increase the length of w (corresponding to the vertical axis), and cause a smaller increase in the horizontal parameters (x and 1/ '); moreover, the increments would advance with the atomic weight of the replacing metal.
The stone knives, arrowheads, celts, hoe-blades, hammers, nails, awls, etc., associated with this pottery are of kinds which though simple and often crude in type are nevertheless not early, but date from the transition period to the age of metal and the earliest centuries of the latter period.
We see however the similarity of the metal-working of both countries at approximately the same time; both are in the same style of artistic development, the Egyptian perhaps the more advanced of the two, and (if the published analysis by Mosso is to be relied upon) with the additional technique of the alloy with tin, making the metal bronze, and so easier for the heads to be cast.
They made a greater display of brilliant metal and gorgeous colour than the Roman armies, for instance.
The shell thus formed is then cut along the line of the intended equator into two hemispheres, they are then again glued together and made to revolve round an axis the ends of which passed through the poles and entered a metal meridian circle.
All these globes are of metal (bronze), or they might not have survived so many years.
He was distinguished as the discoverer of radioactivity, having found in 1896 that uranium at ordinary temperatures emits an invisible radiation which in many respects resembles Rntgen rays, and can affect a photographic plate after passing through thin plates of metal.
Thereupon Ormazd will hold a judicium universale, in the form of a general ordeal, a great test of all mankind by fire and molten metal, and will judge strictly according to justice, punish the wicked, and assign to the good the hoped-for reward.
The proportion of imports taken from the United States is greatest in foodstuffs, metals and metal manufactures, timber and furniture, mineral oils and lard.
Mehner patented heating the oxides of silicon, boron or magnesium with coal or coke in an electric furnace, and then passing in nitrogen, which forms, with the metal liberated by the action of the carbon, a readily decomposable nitride.
Chief among them are weaving and leather and metal work, carried on by the workmen in their own houses.
There are extensive coal-fields and important iron, metal and machine industries, together with the manufacture of chemicals and corn-milling.
It is some five feet long, ending at the top in a crook (volute) bent inwards, and made of metal, ivory or wood.
If of metal, it is hollow; if of wood, it is usually covered with metal.
The chief features of the museum are collections of the fossils, birds and flora of Wales and of obsolete Welsh domestic appliances, casts of the pre-Norman monuments of Wales, and reproductions of metal and ivory work illustrating various periods of art and civilization.
Berzelius stated that neutral salt solutions could be decomposed by electricity, the acid appearing at one pole and the metal at the other.
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.
The electromotive force of Volta's simple cell falls off rapidly when the cell is used, and this phenomenon was shown to be due to the accumulation at the metal plates of the products of chemical changes in the cell itself.
Thus the hydroxyl mentioned above decomposes into water and oxygen, and the chlorine produced by the electrolysis of a chloride may attack the metal of the anode.
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.
Plates of platinum and pure or amalgamated zinc are separated by a porous pot, and each surrounded by some of the same solution of a salt of a metal more oxidizable than zinc, such as potassium.
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.
In the latter case, the tendency of the metal to dissolve in the more dilute solution is greater than its tendency to dissolve in the more concentrated solution, and thus there is a decrease in available energy when metal dissolves in the dilute solution and separates in equivalent quantity from the concentrated solution.
Now the effective change produced by the action of the current is the concentration of the more dilute solution by the dissolution of metal in it, and the dilution of the originally stronger solution by the separation of metal from it.
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.
The phenomena of polarization are thus seen to be due to the changes of surface produced, and are correlated with the differences of potential which exist at any surface of separation between a metal and an electrolyte.
In contact with a solvent a metal is supposed to possess a definite solution pressure, analogous to the vapour pressure of a liquid.
Metal goes into solution in the form of electrified ions.
The liquid thus acquires a positive charge, and the metal a negative charge.
When a current passes from an electrolyte to a metal, the electron must be detached from the atom it was accompanying and chemical action be manifested at the electrode.
Marshall, who, in January of the same year, had found the metal near what is now Coloma, Eldorado county.
It is now ready either for incorporation with sulphur and other materials, or for agglomeration into solid masses by means of the masticating machine - an apparatus which consists of a strong cylindrical cast-iron casing, inside which there revolves a metal cylinder with a fluted or corrugated surface.
The principal industries are the iron and metal manufactures, chiefly centred at Steyr.
In the article Electrolysis it is shown how the passage of an electric current through a solution containing metallic ions involves the deposition of the metal on the cathode.
Sometimes the metal is deposited in a pulverulent form, at others as a firm tenacious film, the nature of the deposit being dependent upon the particular metal, the concentration of the solution, the difference of potential between the electrodes, and other experimental conditions.
This can only be effected if the surface of the metal on which the deposit is to be made is chemically clean.
Large metallic surfaces (especially external surfaces) are sometimes plated by means of a "doctor," which, in its simplest form, is a brush constantly wetted with the electrolyte, with a wire anode buried amid the hairs or bristles; this brush is painted slowly over the surface of the metal to be coated, which must be connected to the negative terminal of the electrical generator.
The varnish is then removed, a different design stopped out, and another metal deposited.
It should be mentioned here, however, that solutions which would deposit their metal on any object by simple immersion should not be generally used for electroplating that object, as the resulting deposit is usually non-adhesive.
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.
Others have arranged a means of obtaining high conductivity wire from cathode-copper without fusion, by depositing the metal in the form of a spiral strip on a cylinder, the strip being subsequently drawn down in the usual way; at present, however, the ordinary methods of wire production are found to be cheaper.
During the next eight years he carried out a minute investigation of this metal and its properties.
While determining its atomic weight, he thought it desirable, for the sake of accuracy, to weigh it in a vacuum, and even in these circumstances he found that the balance behaved in an anomalous manner, the metal appearing to be heavier when cold than when hot.
This metal was known to the ancients, and is mentioned in the Old Testament.
Galena (q.v.), the principal lead ore, has a world-wide distribution, and is always contaminated with silver sulphide, the proportion of noble metal varying from about o of or less to o 3%, and in rare cases coming up to 2 or i %.
The extraction of the metal from pure (or nearly pure) galena is the simplest of all metallurgical operations.
In Wales and the south of England the process is conducted in a reverberatory furnace, the sole of which is paved with slags from previous operations, and has a depression in the middle where the metal formed collects to be let off by a tap-hole.
At this stage as a rule some rich slags of a former operation are added and a quantity of quicklime is incorporated, the chief object of which is to diminish the fluidity of the mass in the next stage, which consists in this, that, with closed air-holes, the heat is raised so as to cause the oxide and sulphate on the one hand and the sulphide on the other to reduce each other to metal.
They are long and narrow; the sole is plane, but slopes from the fire-bridge towards the flue, so that the metal runs to the latter end to collect in pots placed outside the furnace.
Charcoal is now added, and the heat urged on to obtain Pressblei, an inferior metal formed partly by the action of the charcoal on the oxide of lead.
In Cumberland, Northumberland, Durham and latterly the United States, the reverberatory furnace is used only for roasting the ore, and the oxidized ore is then reduced by fusion in a low, square blastfurnace (a "Scottish hearth furnace") lined with cast iron, as is also the inclined sole-plate which is made to project beyond the furnace, the outside portion (the "work-stone") being provided with grooves guiding any molten metal that may be placed on the "stone" into a cast iron pot; the "tuyere" for the introduction of the wind was, in the earlier types, about half way down the furnace.
Thus in the Moffett method it is immaterial whether metal or fume is produced, as in either case it is saved and the price is about the same.
The leading products of the blast-furnace are argentiferous lead (base bullion), matte, slag and flue-dust (fine particles of charge and volatilized metal carried out of the furnace by the ascending gas current).
The plant consists of two tilting oval metal pans (capacity 7 tons), one cylindrical crystallizing pot (capacity 22 tons), with two discharging spouts and one steam inlet opening, two lead moulds (capacity 31 tons), and a steam crane.
Pure lead isa feebly lustrous bluishwhite metal, endowed with a characteristically high degree of softness and plasticity, and almost entirely devoid of elasticity.
Pure lead is far more readily corroded than a metal contaminated with 1% or even less of antimony or copper.
Dilute nitric acid readily dissolves the metal, with formation of nitrate Pb(N03)2.
These salts are like those of tin; and the resemblance to this metal is clearly enhanced by the study of the alkyl compounds.
Lead nitrate, Pb(N03)2, is obtained by dissolving the metal or oxide in aqueous nitric acid; it forms white crystals, difficultly soluble in cold water, readily in hot water and almost insoluble in strong nitric acid.
When mixed with sodium carbonate and heated on charcoal in the reducing flame lead salts yield malleable globules of metal and a yellow oxide-ring.
The metal itself is not used in medicine.
Some cotton is grown, although the soil is as a whole poor; the manufactures include salt, metal vessels and stone handmills.
Thus the vessels used at the Passover are "kosher," as are also new metal vessels bought from a Gentile after they have been washed in a ritual bath.
If one pole of the bar-magnet is brought near the compass, it will attract the opposite pole of the compass-needle; and the magnetic action will not be sensibly affected by the interposition between the bar and the compass of any substance whatever except iron or other magnetizable metal.
Many of the physical properties of a metal are affected by magnetization.
The resultant magnetic field, therefore, is compounded of two fields, the one being due to the poles, and the other to the external causes which would be operative in the absence of the magnetized metal.
In certain cases, as, for instance, in an iron ring wrapped uniformly round with a coil of wire through which a current is passing, the induction is entirely within the metal; there are, consequently, no free poles, and the ring, though magnetized, constitutes a poleless magnet.
Thus it happens that there is no definite relation between the magnetization of a piece of metal which has been previously magnetized and the strength of the field in which it is placed.
The ratio of the residual magnetization to its previous maximum value measures the retentiveness, or retentivity, of the metal.'
A metal which has great retentiveness may at the same time have small coercive force, and it is the latter quality which is of chief importance in permanent magnets.
In the middle part of a rod which has a length of 400 or 500 diameters the effect of the ends is insensible; but for many experiments the condition of endlessness may be best secured by giving the metal the shape of a ring of uniform section, the magnetic field being produced by an electric current through a coil of wire evenly wound round the ring.
In order to attain this result it was formerly the practice to raise the metal to a bright red heat, and allow it to cool while carefully guarded from magnetic influence.
This operation, besides being very troublesome, was open to the objection that it was almost sure to produce a material but uncertain change in the physical constitution of the metal, so that, in fact, the results of experiments made before and after the treatment were not comparable.
By means of a simple arrangement, which will be described farther on, this process can be carried out in a few seconds, and the metal can be brought as often as desired to a definite condition, which, if not quite identical with the virgin state, at least closely approximates to it.
If the wire consists of a ferromagnetic metal, it will become " circularly magnetized by the field, the lines of magnetization being, like the lines of force, concentric circles.
The magnetic condition assumed by a piece of ferromagnetic metal in different circumstances is determinable by various modes of experiment which may be classed as magnetometric, ballistic, and traction methods.
C is a " compensating coil " consisting of a few turns of wire through which the magnetizing current passes; it serves to neutralize the effect produced upon the magnetometer by the magnetizing coil, and its distance from the magnetometer is so adjusted that when the circuit is closed, no ferromagnetic metal being inside the magnetizing coil, the ti, magnetometer needle undergoes no deflection.
If it is desired to annihilate the hysteretic effects of previous magnetization and restore the metal to its original condition; it may be demagnetized by reversals.
The distinguishing feature of the first is the steepness of its outlines; this indicates that the induction increases rapidly in relation to the magnetic force, and hence the metal is well suited for the construction of dynamo magnets.
The second has a very small area, showing that the work done in reversing the magnetization is small; the metal is therefore adapted for use in alternating current trans formers.
On the other hand, the form of the third curve, with its large intercepts on the axes of H and B, denotes that the specimen to which it relates possesses both retentiveness and coercive force in a high degree; such a metal would be chosen for making good permanent magnets.
Denoting by W the work in ergs done upon a cubic centimetre of the metal (=_fHdB or f HdI), he finds W =nips approximately, where n 47r is a number, called the hysteretic constant, depending upon the metal, and B is the maximum induction.
After pointing out that, since the magnetization of the metal is the quantity really concerned, W is more appropriately expressed in terms of I, the magnetic moment per unit of volume, than of B, he suggests an experiment to determine whether the mechanical work required to effect the complete magnetic reversal i Phil.
When in this condition the metal is popularly said to be " saturated."
The magnetic quality of a sample of iron depends very largely upon the purity and physical condition of the metal.
A very pure form of iron, which from the method of its manufacture is called " steel," is now extensively used for the construction of dynamo magnets; this metal sometimes contains not more than 0.3% of foreign substances, including carbon, and is magnetically superior to the best commercial wrought iron.
The following table shows some results of other experiments in which H was believed to have sensibly the same value inside as outside the metal.
Experiments with annealed iron gave less satisfactory results, on account of the slowness with which the metal settled down into a new magnetic state, thus causing a " drift " of the magnetometer needle, which sometimes persisted for several seconds.
Changes Of Dimensions Attending Magnetization It is well known that the form of a piece of ferromagnetic metal is in general slightly changed by magnetization.
Similar results were obtained with three different samples of the metal.
For steel which has been made redhot, suddenly cooled, and then let down to a yellow temper, the critical value of the magnetizing force is smaller than for steel which is either softer or harder; it is indeed so small that the metal contracts like nickel even under weak magnetizing forces, without undergoing any preliminary extension that can be detected.
Some experiments were next undertaken with the view of ascertaining how far magnetic changes of length in iron were dependent upon the hardness of the metal, and the unexpected result was arrived at that softening produces the same effect as tensile stress; it depresses the elongation curve, diminishing the maximum extension, and reducing the " critical value " of the magnetizing force.
Hence the changes of volume undergone by a given sample of wrought iron under increasing magnetization must depend largely upon the state of the metal as regards hardness; there may be always contraction, or always expansion, or first one and then the other.
The width of the gap may be diminished until it is no greater than the distance between two neighbouring molecules, when it will cease to be distinguishable, but, assuming the molecular theory of magnetism to be true, the above statement will still hold good for the intermolecular gap. The same pressure P will be exerted across any imaginary section of a magnetized rod, the stress being sustained by the intermolecular springs, whatever their physical nature may be, to which the elasticity of the metal is due.
Thomson, who, from the results of Bidwell's observations on the magnetic deformation of cobalt, was led to expect that that metal would exhibit a reversal opposite in character to the effect observed in iron.
The wire is subject to two superposed magnetizations, the one longitudinal, the other circular, due to the current traversing the wire; the resultant magnetization is consequently in the direction of a screw or spiral round the wire, which will be right-handed or left-handed according as the relation between the two magnetizations is right-handed or left-handed; the magnetic expansion or contraction of the metal along the spiral lines of magnetization produces the Wiedemann twist.
And, other conditions remaining unchanged, the " sense " of any effect depends upon the nature of the metal under test, and (sometimes) upon the intensity of its magnetization.
Ordinary magnetizable iron is in many respects an essentially different substance from the non-magnetizable metal into which it is transformed when its temperature is raised above a certain point.
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.
The temperature was determined by a platinum-rhodium and platinum thermo-j unction in contact with the metal.
The first immersion into liquid air generally produced a permanent decrease of magnetic moment, and there was sometimes a further decrease when the metal was warmed up again; but after a few alternations of temperature the changes of moment.
Heusler 2 in 1903 that certain alloys of the non-magnetic metal manganese with other non-magnetic substances were strongly magnetizable, their susceptibility being in some cases equal to that of cast 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.
Guillaume 6 explains the ferromagnetism of Heusler's alloy by supposing that the naturally low critical temperature of the manganese contained in it is greatly raised by the admixture of another appropriate metal, such as aluminium or tin; thus the alloy as a whole becomes magnetizable at the ordinary temperature.
The magnetization curve was found to be of the same general form as that of a paramagnetic metal, and gave indications that with a sufficient force magnetic saturation would probably be attained.
Hall Efect.-If an electric current is passed along a strip of thin metal, and the two points at opposite ends of an equipotential line are connected with a galvanometer, its needle will of course not be deflected.
The tranverse electromotive force is equal to KCH/D, where C is the current, H the strength of the field, D the thickness of the metal, and K a constant which has been termed the rotatory power, or rotational coefficient.
Electro-Thermal Relations.-The Hall electromotive force is only one of several so-called " galvano-magnetic effects " which are observed when a magnetic field acts normally upon a thin plate of metal traversed by an electric current.
He considers that Hall's is the fundamental phenomenon, and that the Nernst effect is essentially identical with it, the primary electromotive force in the case of the latter being that of the Thomson effect in the unequally heated metal, while in the Hall experiment it is derived from an external source.
Nickel when magnetized is always positive to the unmagnetized metal.
Weber's theory, the molecules of a ferromagnetic metal are small permanent magnets, the axes of which under ordinary conditions are turned indifferently in every direction, so that no magnetic polarity is exhibited by the metal as a whole; a magnetic force acting upon the metal tends to turn the axes of the little magnets in one direction, and thus the entire piece acquires the properties of a magnet.
In 1855, ignorant of what Wailer had done ten years previously, he succeeded in obtaining metallic aluminium, and ultimately he devised a method by which the metal could be prepared on a large scale by the aid of sodium, the manufacture of which he also developed.
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.
But having failed, he allowed the paper, and also a second by Chevenix of the same tenor in 1805, to be read without avowing that it was he himself who had originally detected the metal, although he had an excellent opportunity of stating the fact in 1804 when he discussed the substance in the paper which announced the discovery of rhodium.
In these instruments the lines are ruled upon a spherical surface of speculum metal, and mark the intersections of the surface by a system of parallel and equidistant planes, o; of which the middle member passes through the centre of the sphere.
Rutherfurd introduced into common use the reflection grating, finding that speculum metal was less trying than glass to the diamond point, upon the permanence of which so much depends.
As a source of light he used sunshine passing through a very small hole perforated in a metal plate, or condensed by a lens of short focus.
The pyramidions were sheathed in bright metal, catching and reflecting the sun's rays as if they were thrones of the sunlight.
In 1789 Klaproth isolated from pitchblende a yellow oxide which he viewed as the oxide of a new metal, which he named uranium, after the newly discovered planet of Herschel.
Like Fe 2 0 3, the yellow oxide lost 48 parts of oxygen per Ur203 (= 864 parts) as water, while Ur 2 = 816 parts of metal remained.
These results were adopted until Peligot in 1840 discovered that Berzelius's (and Klaproth's) metal contains oxygen, and that his (Ur 2) 0 3 really is (U606) 03= 3U 2 0 3, where U= 120 is one equivalent weight of real uranium.
Peligot's results, though called in question by Berzelius, have been amply confirmed by all subsequent investigators; only now, on theoretical grounds, first set forth by Mendeleeff, we double Peligot's atomic weight, so that U now signifies 240 parts of uranium, while UO 3 stands as the formula of the yellow oxide, and UO 2 as that of Berzelius's metal.
To extract the metal, the pitchblende is first roasted in order to remove the arsenic and sulphur.
One method for this purpose is to convert it into a solution of the nitrate U02(N03)2, and from it to precipitate the metal as oxalate by oxalic acid (Peligot).
Uranium is a white malleable metal, which is pretty hard, though softer than steel.
The compact metal when exposed to the air tarnishes only very slowly.
Uranous Compounds.-Uranium dioxide, UO 2 (Berzelius's metal), is a brown to copper-coloured powder, obtained by heating U308 or uranyl oxalate in hydrogen.
The gold is found in minute particles arid in the richest ores the metal is rarely in visible quantities before treatment.
Being a component of bronze, it was used as a metal thousands of years prior to the dawn of history; but it does not follow that prehistoric bronzes were made from metallic tin.
When the unalloyed metal was first introduced cannot be ascertained with certainty.
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.
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.
In the English process the bars are heated cautiously on an inclined hearth, when relatively pure tin runs off, while a skeleton of impure metal remains.
The metal run off is further purified by poling, i.e.
This operation is no doubt intended to remove the oxygen diffused throughout the metal as oxide, part of it perhaps chemically by reduction of the oxide to metal, the rest by conveying the finely diffused oxide to the surface and causing it to unite there with the oxide scum.
After this the metal is allowed to rest for a time in the pot at a temperature above its freezing point and is then ladled out into ingot forms, care being taken at each stage to ladle off the top stratum.
To test the purity of the metal the tin-smelter heats the bars to a certain temperature just below the fusing point, and then strikes them with a hammer or lets them fall on a stone floor from a given height.
The metal is pretty soft and easily flattened out under the hammer, but almost devoid of tenacity.
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.
For making tin-foil the metal is rolled into thin sheets, pieces of which are beaten out with a wooden mallet.
In the absence of metallic tin there is no visible change; but, as soon as the metal is introduced, an electrolytic action sets in and the articles get coated over with a firmly adhering film of tin.
The iron plates, having been carefully cleaned with sand and hydrochloric or sulphuric acid, and lastly with water, are plunged into heated tallow to drive away the water without oxidation of the metal.
Precipitated stannous hydrate dissolves readily in caustic potash; if the solution is evaporated quickly it suffers decomposition, with formation of metal and stannate, 2SnO+2KOH = K2Sn03+Sn+H20.
Flores stanni is a finely divided mixture of the metal and oxide obtained by fusing the metal in the presence of air for some time.
Tin compounds when heated on charcoal with sodium carbonate or potassium cyanide in the reducing blowpipe flame yield the metal and a scanty ring of white Sn02.
I I) is difficult to explain, though Maimonides perhaps correctly regarded the law as a protest against heathenism (on the magical use of representatives of the animal and vegetable kingdom, in conjunction with a metal ring, see I.
It is not necessary for the blocks of wet guncotton to be actually in contact if they be under water, and the peculiar explosive wave can also be conveyed a little distance by a piece of metal such as a railway rail.
The triazoles behave as weak bases, the imido-hydrogen being replaceable by metal.
In metal mining, when the workable portions of the deposit are small and separated by unworkable areas, the levels serve also the purpose of exploration, and in such cases must not be so far apart as to risk missing valuable mineral.
In metal mines, where, as a rule, mechanical haulage is inapplicable, the cars are moved by men (trammers).
Animal haulage is employed chiefly in collieries and large metal mines; sometimes for main haulage lines, but oftener for distributing empty cars and making up trains for mechanical haulage.
Cages of the size generally used in metal mines will hold from ten to fifteen and occasionally twenty men.
In metal mines, however, artificial ventilation is rarely attempted, and natural ventilation often fails to furnish a sufficient quantity of air.
The examination of the air of metal mines has shown that in most cases it is much worse than the air of crowded theatres or other badly ventilated buildings.
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.
On the other hand in the case of uncertain and irregular deposits, the value of which varies between very wide limits, as, for example - in most metal mines and especially mines of gold and silver - a very large number of samples must be taken - sometimes not more than two or three feet apart - in order that the average value of the ore may be known within reasonable limits of error.
A fire underground speedily becomes formidable, not only in coal but also in metal mines, on account of the large quantity of timber used to support the excavations.
In the metal mines of Cornwall and Devon special rules are now in force requiring the use of water in drilling, and other precautions, to lessen this danger from dust.
The cock is now shut against both communications, the reservoir lifted, the gas contents of A discharged and so on, until, when after an exhaustion mercury is let into A, the metal strikes against the top without interposition of a gas-bell.
The same oxide may produce different colours with different glass-mixtures, and different oxides of the same metal may produce different colours.
The bowl is now severed from its blowing iron and the unfinished wine-glass is supported by its foot, which is attached to the end of a working rod by a metal clip or by a seal of glass.
Flashed glass is produced by taking either the first or the last gathering in the production of a cylinder out of a crucible containing the coloured " metal," the other gatherings being taken out of ordinary white sheet-glass.
It is probable that when the metal rod was withdrawn the vessel was filled with sand, to prevent collapse, and buried in heated ashes to anneal.
Threads of coloured molten glass were spirally coiled round the body, and, whilst still viscid, were dragged into zigzags with a metal hook.
To make a really good mirror of glass two things are required - a plate free from bubbles and striae, and a method of applying a film of metal with a uniform bright surface free from defects.
Evelyn notes in his Diary a visit in 1673 to the Italian glass-house at Greenwich, " where glass was blown of finer metal than that of Murano," and a visit in 1677 to the duke of Buckingham's glass-works, where they made huge " vases of mettal as cleare, ponderous and thick as chrystal; also looking-glasses far larger and better than any that came from Venice."
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.
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.
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.
This term of course includes as special cases the qualities of "malleability" (capability of being flattened out under the hammer) and "ductility" (capability of being drawn into wire); but these two special qualities do not always go parallel to each other, for this reason amongst others - that ductility in a higher degree than malleability is determined by the tenacity of a metal.
In the case of iron, however, this applies only if the metal is perfectly pure.
What we have called plasticity must not be confused with the notion of "softness," which means the degree of facility with which the plasticity of a metal can be discounted.
By an hydraulic press a pressure of 100,000 kilos was made to act upon the disks, when the metal was seen to "flow" out of the hole like a viscid liquid.
By the "hardness" of a metal we mean the resistance which it offers to the file or engraver's tool Taking it in this sense, it does not necessarily measure, e.g.
It has in general one value for the powdery metal as obtained by reduction of the oxide in hydrogen below the melting point of the metal, another for the metal in the state which it assumes spontaneously on freezing, and this latter value, in general, is modified by hammering, rolling, drawing, &c. These mechanical operations do not necessarily add to the density; stamping, it is true, does so necessarily, but rolling or drawing occasionally causes a diminution of the density.
But in regard to their power of retaining their magnetism none of them comes at all up to the compound metal steel.
The compounds formed in the first case, which may be either definite chemical compounds or solid solutions, are discussed under Alloys; in this place only combinations with non-metals are discussed, it being premised that the free metal takes part in the reaction.
Arsenic combines readily with all metals into true arsenides, which latter, in general, are soluble in the metal itself.
The presence in a metal of even small proportions of arsenide generally leads to considerable deterioration in mechanical qualities.
The metals to be referred to are always understood to be given in the compact (frozen) condition, and that, wherever metals are enumerated as being similarly attacked, the degree of readiness in the action is indicated by the order in which the several members are named - the more readily changed metal always standing first.
Aluminium is barely affected even at a white heat, if it is pure; the ordinary impure metal is liable to be very readily oxidized.
There is hardly a single metal which holds out against the alkalis themselves when in the state of fiery fusion; even platinum is most violently attacked.
Of the several products, the chlorides of gold and platinum (AuC13 and PtC1 4) are the only ones which when heated beyond their temperature of formation dissociate into metal and chlorine.
Among the native artificers the metal workers and leather dressers are noted.
Again, by raising the temperature, a metal in the solid state can be melted and liquefied, and poured into a mould to assume any form desired, which is retained when the metal cools and solidifies again; the gaseous state of a metal is revealed by the spectroscope.
As the molten metal is run in, the upward thrust on the outside mould, when the level has reached PP', is the weight of metal in the volume generated by the revolution of APQ; and this, by a theorem of Archimedes, has the same volume as the cone ORR', or rya, where y is the depth of metal, the horizontal sections being equal so long as y is less than the radius of the outside FIG.
Afterwards, when the metal has risen above B, to the level KK', the additional thrust is the weight of the cylinder of diameter KK' and height BH.
The upward thrust is the same, however thin the metal may be in the interspace between the outer mould and the core inside; and this was formerly considered paradoxical.
The characters of the syllabary were all arranged and named, and elaborate lists of them were drawn up. The literature was for the most part inscribed with a metal stylus on tablets of clay, called laterculae coctiles by Pliny; the papyrus which seems to have been also employed has perished.
In 1785 appeared his Recherches theoriques et experimentales sur la force de torsion et sur l'elasticite des fils de metal, &c. This memoir contained a description of different forms of his torsion balance, an instrument used by him with great success for the experimental investigation of the distribution of electricity on surfaces and of the laws of electrical and magnetic action, of the mathematical theory of which he may also be regarded as the founder.
Zinc as a component of brass (XaXKOs, 6pei-XaXKos) had currency in metallurgy long before it became known as an individual metal.
Aristotle refers to brass as the "metal of the Mosynoeci," 2 which is produced as a bright and light-coloured XaXK6s, not by addition of tin, but by fusing up with an earth.
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.
From his account it is quite clear that that metal was zinc, but he did not recognize it as the metal of calamine.
The former contains a mixture of semi-solid and molten metal, which is raked out into iron ladles and cast into plates of 66 to 77 lb weight, to be sold as "spelter."
The contents of the iron recipient consist of a powdery mixture of oxide and metal, which is added to the next charge, except what is put aside to be sold as "zinc dust."
The men who charge and empty the retorts, those who draw and cast the metal, and those who keep the furnace in repair, need not know anything about the making or using of gas, and the men who make the gas need not know anything about a zinc furnace.
Furthermore, with the large furnaces which gas-firing makes possible mechanical appliances may be substituted for manual labour in many operations, such as removing and replacing broken retorts, mixing and conveying the charge, drawing and casting the metal, charging and emptying the retorts, and removing the residues and products.
It is generally recognized that the purest ores produce the purest metal.
Grades of commercial zinc are usually based on selected ores, and brands, when they mean anything, usually mean that the metal is made from certain ores.
Chemical control of the metal purchased is not nearly as common as it should be, and the refining of zinc is at best an imperfect operation.
To obtain the metal chemically pure a specially prepared pure oxide or salt of zinc is distilled.
A bath, even of very impure zinc, is allowed to stand at about the temperature of the melting-point of the metal for forty-eight or more hours, whereupon the more easily oxidizable impurities can be largely removed in the dross at the top, the heavier metals such as lead and iron settling towards the bottom.
As each retort in a furnace is in all essentials a separate crucible, and as the metal from only a few of them goes into a single ingot, there can be no uniformity either in the ingots made from the same furnace during a day's run or in those made from several furnaces treating the same ore.
Borchers, trace it to the presence of oxide, produced, for example, either by the use of a solution containing a trace of basic salt of zinc (to prevent which the bath should be kept just - almost imperceptibly - acid), or by the presence of a more electro-negative metal, which, being co-deposited, sets up local action at the expense of the zinc. Many processes have been patented, the ore being acted upon by acid, and the resulting solution treated, by either chemical or electrolytic means, for the successive removal of the other heavy metals.
Properties Zinc is a bluish-white metal, showing a high lustre when freshly fractured.
Sculpture and Carving.Sculpture in wood and metal is ol ancient date in Japan.
Setting aside rude prehistoric essays in stone and metal, which have special interest for the antiquary, we have examples of sculpture in wood and metal, magnificent in conception and technique, dating from the earliest periods of what we may term historical Japan; that is, from near the beginning of the great Buddhist propaganda under the emperor Kimmei (540571) and the princely hierarch, ShOtoku Taishi (573621).
The metal guard (Isuba), made of ironorpreciousalloy,wasadorned with engraved designs, often inlaid with gold and silver.
The kodzuka, or handle of a little knife implanted into the sheath of the short sword or dagger, was, also of metal and engraved with like care.
There is a radical difference between the points of view of the Japanese and the Western connoisseur in estimating tbe Japanese merits of sculpture in metal.
The Japanes kinzoku-shi (metal sculptor) uses thirty-six principal classes 0, chisel, each with its distinctive name, and as most of thes classes comprise from five to ten sub-varieties, his cuttinl and graving tools aggregate about two hundred and fifty.
There is scarcely any limit to the ingenuity and skill of the Japanese expert in diapering a metal surface.
Great importance has always been attached by Japanese experts to the patina of metal used for artistic chiselling.
Neither metal, when it emerges from the furnace, has any beauty, shakudo being simply dark-colored copper and shibuichi pale gun-metal.
The same fundamental rule applied, too, whether the field of the decoration was silk, paper or metal.
Yet another and very favorite method, giving beautiful results, is to model the design on both faces of the metal so as to give a sculpture in the round.
In the surface of the metal the workman cuts grooves wider at the base than at the top, and then hammers into them gold or silver wire.
Thus, for a diamond-petal diaper the chisel is carried across the face of the metal horizontally, tracing a number of parallel bands divided at fixed intervals by ribs which are obtained by merely straightening the chisel and striking it a heavy blow.
The metal is then heated, not to redness, but sufficiently to develop a certain degree of softness, and the workman, taking a very thin sheet of gold (or silver), hammers portions of it into the salient points of the design.
A third kind of inlaying, peculiar to Japan, is sumi-zogan (ink-inlaying), so called because the inlaid design gives the impression of having been painted with Indian ink beneath the transparent surface of the metal.
The difference between this process and ordinary inlaying is that for sumi-zogan the design to be inlaid is fully chiselled out of an independent block of metal with sides sloping so as to be broader at the base than at the top. The object which is to receive the decoration is then channelled in dimensions corresponding to those of the design block, and the latter having been fixed in the channels, the surface is ground and polished until an intimate union is obtained between the inlaid design and the metal forming its field.
Very beautiful effects are thus produced, for the design seems to have grown up to the surface of the metal field rather than to have been planted in it.
The clay having been removed, another plate of the same metal is beaten in, and the same process is repeated.
Iron was the metal used exclusively for work of this kind down to the 16th century, but various metals began thenceforth to be combined.
The decorative design having been completely chiselled in the round, is then fixed in a field of a different metal, in which a design of exactly similar outline has been cut out.
Microscopic accuracy has to be attained in cutting out the space for the insertion of the design, and while the latter must be soldered firmly in its place, not the slightest trace of solder or the least sign of junction must be discernible between the metal of the inserted picture and that of the field in which it is inserted.
He belongs to a class of experts called uchi,nono-shi (hammerers) who perform preparatory work for glyptic artists in metal.
The charm of these methods is that certain parts of the decorative design seem to float, not on the surface of the metal, but actually within it, an admirable effect of depth and atmosphere being thus produced.
In this exquisite and ingenious kind of work the design appears to be growing up from the depths of the metal, and a delightful impression of atmosphere and water is obtained.
Bronze is called by the Japanese kara-kane, a term signifying Chinese metal and showing clearly the source from which knowledge of the alloy was obtained.
From the time when they began to cast bronze statues, Japanese experts understood how to employ a hollow, removable core round which the metal was run in a skin just thick enough for strength without waste of material; and they also understood the use of wax for modelling purposes.
Many brilliant specimens of these mens work survive, their general features being that the motives are naturalistic, that the quality of the metal is exceptionally fine, that in addition to beautifully clear casting obtained by highly skilled use of the cera-perduta process, the chisel was employed to impart delicacy and finish to the design, and that modelling in high relief is most successfully introduced.
Sometimes painting is introduced into these panels and lacquer and metal clasps are added to the ribs.
In the beginning of the 19th century worked ShOkwasai, who frequently collaborated with the metal-worker Shibayama, encrusting his lacquer with small decorations in metal by the latter.
In fine specimens the workmanship is extraordinarily minute, and every fragment of metal, shell, ivory or bone, used to construct the decorative scheme, is imbedded firmly in its place.
The design is generally framed at the outset with a ribbon of thin metal, precisely after the manner of ordinary cloisonn ware.
The artists great difficulty is to hide the metal base completely.
A monochrome loses much of its attractiveness when the color merges into a metal rim, or when the interior of a vase is covered with crude unpolished paste.
In other words, a suitable design is chiselled in the metal base so as to be visible through Translucid the diaphanous enamel.
The principle usually followed in the electrolytic refining of metals is to cast the impure metal into plates, which are exposed as anodes in a suitable solvent, commonly a salt of the metal under treatment.
The metal to be refined passing into solution is concurrently deposited at the cathode.
Soluble impurities which are more electro-negative than the metal under treatment must, if present, be removed by a preliminary process, and the voltage and other conditions must be so selected that none of the more electro-positive metals are co-deposited with the metal to be refined.
When an aqueous solution of the salt of an alkali metal is electrolysed, the Date.
Many electrolytic methods have been proposed for the purification of sugar; in some of them soluble anodes are used for a few minutes in weak alkaline solutions, so that the caustic alkali from the cathode reaction may precipitate chemically the hydroxide of the anode metal dissolved in the liquid, the precipitate carrying with it mechanically some of the impurities present, and thus clarifying the solution.
Yarnold's process, using corrugated glass plates coated on one side with gold or other metal leaf, is stated to have yielded as much as 2700 grains per e.h.p. hour.
This and other reasons led to his rejection of the dualistic hypothesis and the adoption, on the ground of probability, and much more from convenience, of the tenet that " acids are particular compounds of hydrogen, in which the latter can be replaced by metals "; while, on the constitution of salts, he held that " neutral salts are those compounds of the same class in which the hydrogen is replaced by its equivalent in metal.
It is apparent that metallic salts of organic acids would, in aqueous solution, be ionized, the positive ion being the metal, and the negative ion the acid residue.
The oxalates are.readily decomposed onheating, leaving a residue of carbonate, or oxide of the metal.
The silver salt decomposes with explosive violence, leaving a residue of the metal.
It would seem, indeed, that any process by which the particles of two metals are intimately mingled and brought into close contact, so that diffusion of one metal into the other can take place, is likely to result in the formation of an alloy.
The freezing surface, in this case, consists of three sheets each starting from an angular point of the surface, that is, from the freezing-point of a pure metal.
The electrical conductivity of a metal is often very much decreased by alloying with it even small quantities of another metal.
When a pure metal is cooled to a very low temperature its electrical conductivity is greatly increased, but this is not the case with an alloy.
The addition of a third metal will sometimes render the mixture of two other metals homogeneous.
Their experiments, although not conclusive, appear to indicate that the molecule of a metal when in dilute solution often consists of one atom.
It can therefore be employed, instead of that costly metal, in the construction of incandescent lamps where a wire has to be fused into the glass to establish electric connexion between the inside and the outside of the bulb.
If the electrified tray is touched with the sealing-wax or ebonite rod, it will not be discharged, but if touched with a metal wire, the hand, or a damp thread, it is discharged at once.
Cavendish proved it by enclosing a metal sphere in two hemispheres of thin metal held on insulating supports.
The thinnest possible spherical shell of metal, such as a sphere of insulator coated with gold-leaf, behaves as a conductor for static charge just as if it were a sphere of solid metal.
From this fact it follows that we can shield any conductor entirely from external influence by other "charged conductors by enclosing it in a metal case.
Electroscopes and electrometers, therefore, standing in proximity to electrified bodies