Mag., 1898, 46, 261) have investigated the effects of hydrostatic pressure upon magnetization, using the same pieces of iron and nickel as were employed in their experiments upon magnetic change of volume.
Taylor Jones showed in 1897 that only a small proportion of the contraction exhibited by a nickel wire when magnetized could be accounted for on Kirchhoff's theory from the observed effects of pulling stress upon magnetization; and in a more extended series of observations Nagaoka and Honda found wide quantitative divergences between the results of experiment and calculation, though in nearly all cases there was agreement as to quality.
Tomlinson found a critical point in the " temporary magnetization " of nickel (Proc. Phys.
The influence of traction in diminishing the susceptibility of nickel was first noticed by Kelvin (W.
Even under so " moderate " a load as 33 kilogrammes per square mm., the induced magnetization of a hard-drawn nickel wire in a field of 60 fell from 386 to 72 units, while the residual was reduced from about 280 to io.
He jabbed his thumb toward the wall behind him, where she made out the slender nickel doorknob in the space between two shelves of ancient books.
The interspace is filled with a very small quantity of nickel and silver filings, about 95 per cent.
I swear on my old lady's head we never touched a nickel of it—never even opened the damn suitcases.
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.
Currency.The lira (plural lire) of 100 centesimi (centimes) is equal in value to the French franc. The total coinage (exclusive of Eritrean currency) from the 1st of January 1862 to the end of 1907 was 1,104,667,116 lire (exclusive of recoinage), divided as follows: gold, 427,516,970 lire; silver, 570,097,025 lire; nickel, 23,417,000 lire; bronze, 83,636,121 lire.
Rend., 1904 seq.) by fractional crystallization of the nickel double nitrates, the ethyl sulphates, and the bismuth double nitrates of the terbium earths.
The resulting compound, nickel carbonyl, which was described to the Chemical Society in 1890, is both formed and decomposed within a very moderate range of temperature, and on this fact he based a successful process for the extraction of nickel from its ores.
Nickel, so abundant in the island of New Caledonia, has up to the present been found in none of the Australian states except Queensland and Tasmania.
Iron ore, lignite, copper, mercury, molybdenite, nickel, platinum and other minerals have been found, but the quantity of each is too small, or the quality too poor, for them to be of commercial value.
He found, however, that chromic acid, which he had represented as Cr06, neutralized a base containing 3 the 3 The following symbols were also used by Bergman: W, V, " + ", which represented zinc, manganese, cobalt, bismuth, nickel, arsenic, platinum, water, alcohol, phlogiston.
The condensation of acetylene to benzene is also possible at ordinary temperatures by leading the gas over pyrophoric iron, nickel, cobalt, or spongy platinum (P. Sabatier and J.
If the bead is coloured we may have present: cobalt, blue to violet; copper, green, blue on cooling; in the reducing flame, red when cold; chromium, green, unaltered in the reducing flame; iron, brownish-red, light-yellow or colourless on cooling; in the reducing flame, red while hot, yellow on cooling, greenish when cold; nickel, reddish to brownish-red, yellow to reddish-yellow or colourless on cooling, unaltered in the reducing flame; bismuth, yellowish-brown, light-yellow or colourless on cooling; in the reducing flame, almost colourless, blackish-grey when cold; silver, light yellowish to opal, somewhat opaque when cold; whitish-grey in the reducing flame; manganese, amethyst red, colourless in the reducing flame.
To the filtrate from the aluminium, iron and chromium precipitate, ammonia and ammonium sulphide are added; the precipitate may contain nickel, cobalt, zinc and manganese sulphides.
The next group may contain black nickel and cobalt sulphides, flesh-coloured manganese sulphide, and white zinc sulphide.
Trans., 1900, p. 233) investigated nickel and cobalt over a wide range of temperature (from -182.5° to loo°); his results are: It is evident that the atomic heats of these intimately associated elements approach nearer and nearer as we descend in temperature, approximating to the value 4.
For example, episomorphs of white potash alum and violet chrome alum, of white magnesium sulphate and green nickel sulphate, and of many other pairs of salts, have been obtained.
Nickel and cobalt are also strongly magnetic, and in 1903 the interesting discovery was made by F.
Practically the metals iron, nickel and cobalt, and some of their alloys and compounds constitute a class by themselves and are called ferromagnetic substances.
Shimizu 3 indicate that Steinmetz's formula holds for nickel and annealed cobalt up to B =3000, for cast cobalt and tungsten steel up to B =8000, and for Swedish iron up to B =18,000, the range being in all cases extended at the temperature of liquid air.
During the first stage, when the magnetizing force is small, the magnetization (or the induction) increases rather slowly with increasing force; this is well shown by the nickel curve in the diagram, but the effect would be no less conspicuous in the iron curve if the abscissae were plotted to a larger scale.
Under increasing magnetizing forces, greatly exceeding those comprised within the limits of the diagram, the magAetization does practically reach a limit, the maximum value being attained with a magnetizing force of less than 2000 for wrought iron and nickel, and less than 4000 for cast iron and cobalt.
Mag., 1890, 2 9, 2 53, 2 93) on the magnetization of iron, - nickel, and i cobalt under forces ranging from about 100 to 12 50 units.
The behaviour of nickel in weak fields has been observed by Ewing (Phil.
While therefore the initial susceptibility of nickel is less than that of iron and steel, the range of magnetic force within which it is approximately constant is about one hundred times greater.
Barrett in 1882 that a nickel bar contracts when magnetized, nothing of importance was added by Joule's results for nearly forty years.
Experiments were afterwards made with rods of iron, nickel, and cobalt, the external field being carried up to the high value of 1500 units.
Nickel exhibited retraction from the very beginning (as observed by Barrett), its greatest change of length considerably exceeding that undergone by iron; in a field of Boo the original length was diminished by as much as 1/40,000 part, but stronger forces failed to produce any further effect.
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.
Yet notwithstanding this enormous effect in iron, the action of a current upon nickel and cobalt turned out to be almost inappreciable.
They also tested several varieties of nickel-steel in the form of both ovoids and wires.
Sample containing 25% of nickel no appreciable change was detected; others containing larger percentages, and tested in fields up to 2000, all exhibited elongation, which tended to an asymptotic value as the field was increased.
For soft iron, tungsten-steel and nickel little difference appeared to result from lowering the temperature down to - 186° C. (the temperature of liquid air); at sufficiently high temperatures, 600 to 1000° or more, it was remarked that the changes of length in iron, steel and cobalt tended in every case to become proportional to the magnetic force, the curves being nearly straight lines entirely above the axis.
Honda subjected tubes of iron, steel and nickel to the simultaneous action of circular and longitudinal fields, and observed the changes of length when one of the fields was varied while the other remained constant at different successive values from zero upwards.
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.
Various nickel-steels all expanded under magnetization, the increase being generally considerable and proportional to the field; in the case of an alloy containing 29% of nickel the change was nearly 40 times greater than in soft iron.
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.
Ewing has also examined the effects produced by longitudinal compression upon the susceptibility and retentiveness of nickel, and found, as was to be expected, that both were greatly increased by pressure.