A body made up of molecules of this kind will expand on heating.
A cell when filled with fresh slices becomes the head of the battery, and where skilled scientific control can be relied upon to regulate the process, the best and most economical way of heating the slices, previous to admitting the hot liquor from the next cell, is by direct steam; but as the slightest inattention or carelessness in the admission of direct steam might have the effect of inverting sugar and thereby causing the loss of some portion of saccharine in the slices, water heaters are generally used, through which water is passed and heated up previous to admission to the freshly-filled cell.
A crystalline form was obtained by Debray as olive-green prisms by igniting a mixture of sodium tungstate and carbonate in a current of hydrochloric acid gas, and by Nordenskjold by heating hydrated tungstic acid with borax.
A green pigment known as Rinmann's green is prepared by mixing I oo parts of zinc vitriol with 2.5 parts of cobalt nitrate and heating the mixture to redness, to produce a compound of the two oxides.
A high vacuum is needed for the detection of the minute forces here concerned; but just in that case the indirect radiometereffect of the heating of the residual gas masks the effect.
A pentasulphide B2S5 is prepared, in an impure condition, by heating a solution of sulphur in carbon bisulphide with boron iodide, and forms a white crystalline powder which decomposes under the influence of water into sulphur, sulphuretted hydrogen and boric acid.
A purer product is obtained by heating aluminium turnings in a current of dry chlorine, when the chloride distils over.
A somewhat impure silicon (containing 90-98% of the element) is made by the Carborundum Company of Niagara Falls (United States Patents 745 122 and 842273, 1908) by heating coke and sand in an electric furnace.
A steam heating plant pipes heat to many shops, offices and residences.
A still more potent absorption is afforded by calcium prepared in situ by heating a mixture of magnesium dust with thoroughly dehydrated quick-lime.
A third oil was obtained by heating the liver-residues to above the boiling-point of water, whereupon a black product, technically called "brown oil," separated.
A very gentle heating gives decomposition approximating to the equation of 22KC103=14KC10 4 +8KC1+50 2, whilst on a more rapid heating the quantities correspond more nearly to loKC10 3 = 6KC104+4KC1+ 302.
After four days' heating the provisional front wall is removed piecemeal, and the retorts, after having been heated to redness, are inserted in corresponding sets.
After oxidation, the product is reduced by heating with carbon, care being taken to prevent any loss through volatilization, by covering the mass with a layer of some protective substance such as potash, soda or glauber salt, which also aids the refining.
After the ascending column of gases has done its work of heating and deoxidizing the ore,.
After the outer surface has been scraped and cleaned, the pieces are flattened by heating them over a fire and submitting them to pressure on a flat surface.
Again, the construction of electric furnaces may often be exceedingly crude and simple; in the carborundum furnace, for example, the outer walls are of loosely piled bricks, and in one type of furnace the charge is simply heaped on the ground around the carbon resistance used for heating, without containing-walls of any kind.
Alkyl pyridines -CO /COare also obtained by heating aldehyde ?
All four mono-hydroxyxanthones are known, and are prepared by heating salicylic acid with either resorcin, pyrocatechin or hydroquinone; they are yellow crystalline solids, which act as dyestuffs.
All sugars are colourless solids or syrups, which char on strong heating; they are soluble in water, forming sweet solutions but difficultly soluble in alcohol.
All the iron in the ore generally dissolves upon heating, and a white residue is left.
All the metallic chlorides, with the exception of those of the alkali and alkaline earth metals, are reduced either to the metallic condition or to that of a lower chloride on heating in a current of hydrogen; most are decomposed by concentrated sulphuric acid.
All their endeavours have obtained at best but a doubtful success, for they have overlooked the fact that to evaporate a given weight of water from the syrup in a vacuum pan at least an equal weight (or in practice about 15% more) of steam must be condensed, and the first cost of mechanical agitators, together with the expenditure they involve for motive power and maintenance, must be put against the slight saving in the heating surface effected by their employment.
Alloys of magnesium and silicon are prepared by heating fragments of magnesium with magnesium filings and potassium silico-fluoride.
Alumina is obtained as a white amorphous powder by heating aluminium hydroxide.
Among the leading and more distinctive items were printing and publishing ($21,023,855 in 1905); sugar and molasses refining ($ 1 5,74 6, 547 in 1900; figures not published in 1905 because of the industry being in the hands of a single owner); men's clothing (in 1900, $8,609,475, in 1905, $11,246,004); women's clothing (in 1900, $3,258,483, in 1905, $5,705,470); boots and shoes (in 1900, $3,882,655, in 1905, $5,575,927); boot and shoe cut stock (in 1905, $5, 211, 445); malt liquors (in 1900, $7,518,668, in 1905, $6,715,215); confectionery (in 1900, $4,455,184, in 1905, $6,210,023); tobacco products (in 1900, $3,504,603, in 1905, $4,59 2, 698); pianos and organs ($3,670,771 in 1905); other musical instruments and materials (in 1905, $231,780); rubber and elastic goods (in 1900, $3,139,783, in 1905, $2,887,323); steam fittings and heating apparatus (in 1900, $2,876,327, in 1905, $3,354, 020); bottling, furniture, &c. Art tiles and pottery are manufactured in Chelsea.
An antimony phosphide and arsenide are known, as is also a thiophosphate, SbPS 4, which is prepared by heating together antimony trichloride and phosphorus pentasulphide.
An oxide Th305 is formed by heating the oxalate.
Anthracene has also been obtained by heating ortho-tolylphenyl ketone with zinc dust C6H4(CH CH =H20+C6H4 I)C6H4.
Antimony pentachloride, SbC1 5, is prepared by heating the trichloride in a current of chlorine.
Antimony trioxide occurs as the minerals valentinite and senarmontite, and can be artificially prepared by burning antimony in air; by heating the metal in steam to a bright red heat; by oxidizing melted antimony with litharge; by decomposing antimony trichloride with an aqueous solution of sodium carbonate, or by the action of dilute nitric acid on the metal.
Aposafranone, C,8H12N20, is formed by heating aposafranine with concentrated hydrochloric acid.
Arsenic burns on heating in a current of oxygen, with a pale lavender-coloured flame, forming the trioxide.
Arsenic compounds can be detected in the dry way by heating in a tube with a mixture of sodium carbonate and charcoal when a deposit of black amorphous arsenic is produced on the cool part of the tube, or by conversion of the compound into the trioxide and heating with dry sodium acetate when the offensive odour of the extremely poisonous cacodyl oxide is produced.
As a class, the metallic bromides are solids at ordinary temperatures, which fuse readily and volatilize on heating.
AsCl4CH3, AsCl3(CH3)2, on heating break down, with separation of methyl chloride and formation of compounds of the type AsX3 the breaking down taking place more readily the fewer the number of methyl groups in the compound.
At the same time Berzelius obtained the element, in an impure condition, by fusing silica with charcoal and iron in a blast furnace; its preparation in a pure condition he first accomplished in 1823, when he invented the method of heating double potassium fluorides with metallic potassium.
Azoxy Compounds, R N O N R', are usually yellow or red crystalline solids which result from the reduction of nitro or nitroso compounds by heating them with alcoholic potash (preferably using methyl alcohol).
Baeyer obtained what was probably a mixture of the two by heating I.
Barium hydroxide, Ba(OH) 2, is a white powder that can be obtained by slaking the monoxide with the requisite quantity of water, but it is usually made on the large scale by heating heavy spar with small coal whereby a crude barium sulphide is obtained.
Beilstein determines their presence by heating the substance with pure copper oxide on a platinum wire in the Bunsen flame; a green coloration is observed if halogens be present.
Beryllium chloride BeC1 2, like aluminium chloride, may be prepared by heating a mixture of the oxide and sugar charcoal in a current of dry chlorine.
Berzelius, who prepared tantalic acid from the mineral tantalite in 1820, obtained an impure metal by heating potassium tantalofluoride with potassium.
Bismuth trichloride, BiC13, was obtained by Robert Boyle by heating the metal with corrosive sublimate.
Boiled oil is prepared in a variety of ways - that most common being by heating the raw oil in an iron or copper boiler, which, to allow for frothing, must only be about three-fourths filled.
Boron fluoride also combines with ammonia gas, equal volumes of the two gases giving a white crystalline solid of composition BF 3 NH 3 i with excess of ammonia gas, colourless liquids BF 3.2NH 3 and BF 3.3NH 3 are produced, which on heating lose ammonia and are converted into the solid form.
Boron hydride has probably never been isolated in the pure condition; on heating boron trioxide with magnesium filings, a magnesium boride Mg 3 B 2 is obtained, and if this be decomposed with dilute hydrochloric acid a very evil-smelling gas, consisting of a mixture of hydrogen and boron hydride, is obtained.
Boron nitride BN is formed when boron is burned either in air or in nitrogen, but can be obtained more readily by heating to redness in a platinum crucible a mixture of one part of anhydrous borax with two parts of dry ammonium chloride.
Boron trioxide B203 is the only known oxide of boron; and may be prepared by heating amorphous boron in oxygen, or better, by strongly igniting boric acid.
Bringing such an ingot, then, to the rolling temperature is not really an operation of heating, because its average temperature is already above the rolling temperature, but one of equalizing the temperature, by allowing the internal excess of heat to " soak " through the mass.
But this competition among inventors, whatever the incentive, has not been without benefit, because to-day, by means of very simple improvements in details, such as the addition of circulators and increased area of connexions, what may be taken to be the standard type of multiple-effect evaporator (that is to say, vertical vacuum pans fitted with vertical heating tubes, through which passes the liquor to be treated, and outside of which the steam or vapour circulates) evaporates nearly double the quantity of water per square foot of heating surface per hour which was evaporated by apparatus in use so recently as 1885 - and this without any increase in the steam pressure.
But when exceptionally strong fields are desired, the use of a coil is limited by the heating effect of the magnetizing current, the quantity of heat generated per unit of time in a coil of given dimensions increasing as the square of the magnetic field produced in its interior.
By careful heating it may be made to yield the anhydrous salt.
By electrolysing an aqueous solution of the chloride with a mercury cathode, a liquid and a solid amalgam, SrHgn, are obtained; the latter on heating gives a mixture of Sr 2 Hg 5 and SrHg 5, and on distillation an amalgam passes over, and not the metal.
By gradually heating amber in an oil-bath it becomes soft and flexible.
By heating solutions of certain iron salts for some time and then adding a little sulphuric acid it is precipitated as a brown powder.
By heating the bromate it was partially converted into the bromide, and the resulting mixture was distilled with sulphuric acid.
By heating the disulphide in a current of hydrogen, germanious sulphide, GeS, is formed.
By heating the metal or thallous chloride in chlorine, T1C1 T1C1 3 is obtained, which on further heating gives3TlCI.T1C13.
By heating the nitrate it is obtained as hemimorphous pyramids belonging to the hexagonal system; and by heating the chloride in a current of steam as hexagonal prisms. It is insoluble in water; it dissolves readily in all aqueous acids, with formation of salts.
By heating with a small quantity of magnesium it is converted into germanious oxide, GeO.
By heating with phosphorus pentachloride an alkyl group is eliminated and a chlorcarbonic ester formed.
By heating with sodium amalgam and separating with hydrochloric acid, the dichloride, TaC1 2.2H 2 O, is obtained as emerald green hexagonal crystals.
By passing bromine vapour over red-hot tungsten dioxide a mixture of WO 2 Br 2 and WOBr4 is obtained, from which the latter can be removed by gently heating when it volatilizes.
C 2 H 5 SO 2 C1 (chlorides of sulphonic acids), by heating the salts of esters of sulphuric acid with potassium hydrosulphide, and by heating the alcohols with phosphorus pentasulphide.
C. Gooch, which has come into common use in quantitative analysis where the solid matter has to be submitted to heating or ignition, consists of a crucible having a perforated bottom.
Caesium nitrate, CsNO 3, is obtained by dissolving the carbonate in nitric acid, and crystallizes in glittering prisms, which melt readily, and on heating evolve oxygen and leave a residue of caesium nitrite.
Calcium ferrite, magnesium ferrite and zinc ferrite, ROFe203(R=Ca, Mg, Zn), are obtained by intensely heating mixtures of the oxides; magnesium ferrite occurs in nature as the mineral magnoferrite, and zinc ferrite as franklinite, both forming black octahedra.
Calcium is generally estimated by precipitation as oxalate which, after drying, is heated and weighed as carbonate or oxide, according to the degree and duration of the heating.
Calcium monosulphide, CaS, a white amorphous powder, sparingly soluble in water, is formed by heating the sulphate with charcoal, or by heating lime in a current of sulphuretted hydrogen.
Cerous chloride, CeC1 3, is obtained when the metal is burned in chlorine; when a mixture of cerous oxide and carbon is heated in chlorine; or by rapid heating of the dioxide in a stream of carbon monoxide and chlorine.
Cerous sulphide, Ce2S3, results on heating cerium with sulphur or cerium oxide in carbon bisulphide vapour.
Chemically pure chloride of potassium is most conveniently prepared from the pure perchlorate by heating it in a platinum basin at the lowest temperature and then fusing the residue in a wellcovered platinum crucible.
Chemie, 1868, p. 34), or by heating the sulphonate with sodium formate (V.
Chromic sulphide, Cr2S3, results on heating chromium and sulphur or on strongly heating the trioxide in a current of sulphuretted hydrogen; it forms a dark green crystalline powder, and on ignition gives the sesquioxide.
Chromium as prepared by the Goldschmidt process is in a passive condition as regards dilute sulphuric acid and dilute hydrochloric acid at ordinary temperatures; but by heating the metal with the acid it passes into the active condition, the same effect being produced by heating the inactive form with a solution.
Clean and repair the forcing-houses, and overhaul the heating apparatus to see it is in good working condition.
Columbium oxysulphide, CbOS 3, is obtained as a dark bronze coloured powder when the pentoxide is heated to a white heat in a current of carbon bisulphide vapour; or by gently heating the oxychloride in a current of sulphuretted hydrogen.
Conversely, by heating protocatechuic acid with potash and methylene iodide, piperonylic acid was regained.
Count Gramont 5 has been able to obtain spectro scopic evidence of the metalloids in a mineral by employing powerful condensers and heating the electrodes in an oxyhydro gen flame when these (as is often the case) are not sufficiently conducting.
Crystallized alumina is also obtained by heating the fluoride with boron trioxide; by fusing aluminium phosphate with sodium sulphate; by heating alumina to a dull redness in hydrochloric acid gas under pressure; and by heating alumina with lead oxide to a bright red heat.
Crystals may be obtained by heating di-calcium pyrophosphate, Ca2P207, with water under pressure.
Crystals of ordinary borax swell up to a very great extent on heating, losing their water of crystallization and melting to a clear white glass.
Crystals of quartz may be readily prepared artificially by a number of methods; for example, by heating glass or gelatinous silica with water under pressure.
Cupric chloride, CuC1 2, is obtained by burning copper in an excess of chlorine, or by heating the hydrated chloride, obtained by dissolving the metal or cupric oxide in an excess of hydrochloric acid.
Cupric oxide, CuO, occurs in nature as the mineral melaconite (q.v.), and can be obtained as a hygroscopic black powder by the gentle ignition of copper nitrate, carbonate or hydroxide; also by heating the hydroxide.
Cuprous chloride, CuCl or Cu 2 Cl 21 was obtained by Robert Boyle by heating copper with mercuric chloride.
Davy also described and partially investigated the gas, named by him " euchlorine," obtained by heating potassium chlorate with hydrochloric acid; this gas has been more recently examined by Pebal.
Decker (Ber., 9 5, 38, p. 1144) has found that many ortho substituted quinolines will not combine with methyl iodide owing to steric hindrance, but the difficulty can be overcome in most cases by using methyl sulphate and heating the reaction components to ioo C. for half an hour.
Di-metallic salts are obtained by heating cyanates alone, e.g.
Diamond is insoluble in acid and alkalis, but is oxidised on heating with potassium bichromate and sulphuric acid.
Dorp (Ber.,1874,7,P.578) obtained orthobenzoyl benzoic acid by heating phthalic anhydride with benzene in the presence of aluminium chloride.
During all the latter part of the heating, when the temperature of the ingot has approached that of the flame, only an ever smaller and smaller part of the heat of that flame can be absorbed by the ingots.
Earthy matter and other matter precipitated and fallen on the copper double bottom may be dislodged by a slowly revolving scraper - say every twelve hours - and ejected through the bottom discharge cock; and thus the heating surface of the copper bottom will be kept in full efficiency.
Electrical furnaces have not as yet been employed for ordinary glass-making on a commercial scale, but the electrical plants which have been erected for melting and moulding quartz suggest the possibility of electric heating being employed for the manufacture of glass.
Evaporation of the Juice to Syrup. - The third operation is the concentration of the approximately pure, but thin and watery, juice to syrup point, by driving off a portion of the water in vapour through some system of heating and evaporation.
Exposed to moist air it rapidly oxidizes to the hydroxide; and it burns on heating in air with a yellow flame, yielding the monoxide and dioxide.
Exposure to air gives phosphorous and phosphoric acids, and on heating it gives phosphine and phosphoric acid.
Ferric bromide, FeBr31 is obtained as dark red crystals by heating iron in an excess of bromine vapour.
Ferrous fluoride, FeF21 is obtained as colourless prisms (with 8H2O) by dissolving iron in hydrofluoric acid, or as anhydrous colourless rhombic prisms by heating iron or ferric chloride in dry hydrofluoric acid gas.
Fine aluminium will not burn below the temperature of molten cast iron, and previous experimenters had resorted to heating their mixtures in a crucible.
For heating purposes, the stoves employed are practically kerosene lamps of suitable construction, though gasoline is used as a domestic fuel in the United States.
For specimens of large sectional area it is necessary to apply corrections in respect of the energy dissipated by eddy currents and in heating the secondary circuit.
For the pyroarsenate method it is necessary that the arsenic should be in the arsenic condition, if necessary this can be effected by heating with nitric acid; the acid solution is then mixed with "magnesia mixture" and made strongly alkaline by the addition of ammonia.
Forgetful or ignorant of the great principle announced and established by Rilleux, they have mostly devoted their energies and ingenuity to contriving all sorts of complicated arrangements to give the juice the density required, by passing and repassing it over the heating surface of the apparatus, the saving of a few square feet of which would seem to have been their main object.
Formerly the pans were heated by open firing from below; but now the almost universal practice is to boil by steam injected from perforated pipes coiled within the pan, such injection favouring the uniform heating of the mass and causing an agitation favourable to the ultimate mixture and saponification of the materials.
From 1861-91 methylated spirits prepared in this way were allowed to be sold by retail in Great Britain in small quantities for domestic purposes such as cleaning, heating and lighting; but use in large quantities, or in manufacture, was only possible under special authority and under excise supervision.
From the heating of native calcium sulphate and carbon is obtained calx sulphurata (U.S. and B.P.), or sulphurated lime, a greyish-white powder.
From these acyl derivatives the elements of water are removed, either by simple heating or by boiling their aqueous solution; this elimination is accompanied by the formation of the azoxime ring.
Fuming or Nordhausen Oil of Vitriol, a mixture or chemical com pound of H 2 SO 4, with more or less S03, has been made for centuries by exposing pyritic schist to the influence of atmospheric agents, collecting the solution of ferrous and ferric sulphate thus formed, boiling it down into a hard mass ("vitriolstein") and heating this to a low red heat in small earthenware retorts.
Gallium forms colourless salts, which in neutral dilute aqueous solutions are converted on heating into basic salts.
Gas, obtained by pipe lines from the Ohio-Pennsylvania and the Canadian (Welland) natural gas fields, is also used extensively for lighting and heating purposes.
GayLussac, who obtained it by heating mercury or silver cyanide; this discovery is of considerable historical importance, since it recorded the isolation of a "compound radical."
Glauber showed how to prepare hydrochloric acid, spiritus salis, by heating rock-salt with sulphuric acid, the method in common use to-day; and also nitric acid from saltpetre and arsenic trioxide.
Gold forms three sulphides corresponding to the oxides; they readily decompose on heating.
Guntz and Roederer (Comptes rendus, 1906, 142, p. 400) by heating the hydride in a vacuum to 1000.
Hackspill (Comptes Rendus, 5905, 141, p. 101) finds that metallic caesium can be obtained more readily by heating the chloride with metallic calcium.
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.
He explained this effect by supposing that the Volta contact electromotive force varied with the temperature, so that the exact balance was destroyed by unequal heating.
He takes long weekends every time the weather starts heating up.
Heated in a current of ammonia it gives succinimide, which is also obtained on heating acid ammonium succinate.
Heating by hot water may be said to depend, in part, on the influence of gravity on water being to some extent overcome by heating in a boiler.
Heating Furnaces are used in iron manufacture chiefly for bringing masses of steel or wrought iron to a temperature proper for rolling or forging.
Heating is effected by means of hot-water pipes below the beds, and against the side ventilators.
Heating or exposure to sunlight reduces it to the red oxide; it fires when ground with sulphur, and oxidizes ammonia to nitric acid, with the simultaneous formation of ammonium nitrate.
Heating spirits of hartshorn, he was able to collect "alkaline air" (gaseous ammonia), again because he was using mercury in his pneumatic trough; then, trying what would happen if he passed electric sparks through the gas, he decomposed it into nitrogen and hydrogen, and "having a notion" that mixed with hydrochloric acid gas it would produce a "neutral air," perhaps much the same as common air, he synthesized sal ammoniac. Dephlogisticated air (oxygen) he prepared in August 1774 by heating red oxide of mercury with a burning-glass, and he found that in it a candle burnt with a remarkably vigorous flame and mice lived well.
Held synthesized the acid from ethyl chlor-acetoacetate (from chlorine and acetoacetic ester) by heating with potassium cyanide and saponifying the resulting nitrile.
Henri Moissan obtained the metal of 99% purity by electrolysing calcium iodide at a low red heat, using a nickel cathode and a graphite anode; he also showed that a more convenient process consisted in heating the iodide with an excess of sodium, forming an amalgam of the product, and removing the sodium by means of absolute alcohol (which has but little action on calcium), and the mercury by distillation.
His method consisted in using magnesia instead of lime for the recovery of the ammonia (which occurs in the form of ammonium chloride in the ammonia-soda process), and then by evaporating the magnesium chloride solution and heating the residue in steam, to condense the acid vapours and so obtain hydrochloric acid.
Hittorf's phosphorus is another crystalline allotrope formed by heating phosphorus with lead in a sealed tube to redness, and removing the lead by boiling the product with nitric and hydrochloric acid.
Hot wire voltmeters, like electrostatic voltmeters, are suitable for use with alternating currents of any frequency as well as with continuous currents, since their indications depend upon the heating power of the current, which is proportional to the square of the current and therefore to the square of the difference of potential between the terminals.
Hydrochloric acid gives thallous chloride and chlorine; sulphuric acid gives off oxygen; and on heating it first gives the trioxide and afterwards the monoxide.
Hydrogen may also be obtained by the action of zinc on ammonium salts (the nitrate excepted) (Lorin, Comptes rendus, 1865, 60, p. 745) and by heating the alkali formates or oxalates with caustic potash or soda, Na2C204+2NaOH = H 2 +2Na 2 CO 3.
Hydrolysis by means of acids or alkalis converts the asparagines into aspartic acid; whilst on heating with water in a sealed tube they are converted into ammonium aspartate.
If it were possible to sterilize the must prior to pitching with pure yeast no doubt better results might be obtained, but this appears to be out of the question inasmuch as the heating of the must which sterilization involves is not a practicable operation.
If the heating be with charcoal, the trimetallic salts of the alkalis and alkaline earths are unaltered, whilst the monoand di-salts give free phosphorus and a trimetallic salt.
If the substance to be weighed changes in composition on strong heating, it is necessary to employ a tared filter, i.e.
In 1808 Sir Humphry Davy, fresh from the electrolytic isolation of potassium and sodium, attempted to decompose alumina by heating it with potash in a platinum crucible and submitting the mixture to a current of electricity; in 1809, with a more powerful battery, he raised iron wire to a red heat in contact with alumina, and obtained distinct evidence of the production of an iron-aluminium alloy.
In 1855 C. Brunner described a method for oxidizing the carbon to carbon dioxide, which could be estimated by the usual methods, by heating the substance with potassium bichromate and sulphuric acid.
In a fine state of division it takes fire on heating in air, but is permanent at ordinary temperatures in oxygen or air; it is readily attacked by hydrochloric and sulphuric acids, but scarcely acted on by nitric acid.
In a mine with two shafts a ventilating current may result from other conditions creating a difference in the temperature of the air in either shaft - for example, the cooling effect of dropping water or the heating effect of steam pipes.
In ammeters for small currents it is customary to pass the whole current through the heating wire.
In compressed air at ordinary temperature there is no glowing, but it may be brought about by heating.
In most temperate climates, artificial heating is necessary, at least occasionally, in many cases, but the tendency has been to be more sedulous of warmth than of ventilation.
In order to minimize the heating action of the light, it might be submitted to a preliminary prismatic analysis before it reaches the slit of the spectrometer, after the manner of Helmholtz.
In some English works coal is still employed for direct heating with various forms of mechanical stokers.
In the Brin process for the manufacture of oxygen, barium dioxide is obtained as an intermediate product by heating barium monoxide with air under pressure.
In The Case Of Water Or Other Liquids It Is Necessary To Employ A Platinum Wire Stretched Along The Tube As Heating Conductor.
In the heating operation the surface is charred, and thereby the pores are closed up, and what is termed "nerve" is given to the material.
In the United States the danger of the stoves that used to be employed for heating the interiors of the cars has been realized, and now the most common method is by steam taken from the locomotive boiler and circulated through the train in a line of piping, rendered continuous between the cars by flexible coupling-hose.
In this coal, as well as in the lignite of Tasmania, known as white coal or Tasmanite, the sulphur occurs in organic combination, but is so firmly held that it can only be very partially expelled, even by exposure to a very high and continued heating out of contact with the air.
Instead of heating the tube, the gas may be ignited at the mouth of the tube and a cold surface of porcelain or platinum placed in the flame, when a black deposit is formed on the surface.
Iodine can be readily detected by the characteristic blue coloration that it immediately gives with starch paste; the colour is destroyed on heating, but returns on cooling provided the heating has not been too prolonged.
Iodine in alkaline solution converts pyrrol into iodol (tetra-iodopyrrol), crystallizing in yellowishbrown needles, which decompose on heating.
Iodine may also be prepared by the decomposition of an iodide with chlorine, or by heating a mixture of an iodide and manganese dioxide with concentrated sulphuric acid.
It absorbs ammonia gas, forming the compound FeC12.6NH31 which on heating loses ammonia, and, finally, yields ammonium chloride, nitrogen and iron nitride.
It assumes a metallic lustre on burnishing or heating to redness.
It burns in an atmosphere of chlorine forming the trichloride; it also combines directly with bromine and sulphur on heating, while on fusion with alkalis it forms arsenites.
It burns on heating in air, and is soluble in solutions of alkaline hydroxides and carbonates, forming thioarsenites, As2S3 + 4KOH = K2HAsO3 + K2HAsS3 + 1H2O.
It burns on heating in air; and is scarcely attacked by hydrochloric or nitric acids, or by aqua regia; it is soluble in warm concentrated sulphuric acid.
It can also be prepared by heating borimide B2(NH)31 or by heating boron trioxide with a metallic cyanide.
It can be prepared by the reduction of phenyl propiolic acid with zinc and acetic acid, by heating benzal malonic acid, by the condensation of ethyl acetate with benzaldehyde in the presence of sodium ethylate or by the so-called "Perkin reaction"; the latter being the method commonly employed.
It combines directly with fluorine at Ordinary temperature, and with chlorine, bromine and sulphur on heating.
It combines directly with many metals on heating, whilst others merely dissolve it.
It crystallizes in colourless prisms, possessing a saline taste; it sublimes on heating and is easily soluble in water.
It crystallizes in large transparent prisms, which melt on heating and decompose, leaving a residue of metaphosphoric acid, (HP03).
It crystallizes in long yellow needles and decomposes readily on heating into the monochloride and chlorine.
It decomposes on heating into phosphine and phosphoric acid.
It decomposes violently on heating, and explodes in contact with hydrogen, sulphur, phosphorus, &c. It dissolves in water to form a deep red solution which contains permanganic acid, HMnO 4.
It decomposes water slowly in the cold, and more rapidly on heating.
It deliquesces in moist air, and is easily reduced to arsenic by heating with carbon.
It does not dissociate on heating as do the pentachloride and pentabromide, thus indicating the existence of pentavalent phosphorus in a gaseous compound; dissociation, however, into the trifluoride and free fluorine may be brought about by induction sparks of 150 to 200 mm.
It does not melt at a white heat, and is easily reduced to the metal by heating in a current of hydrogen or with carbon.
It enabled the honey producer to increase his output considerably by extracting honey from the cells in most cleanly fashion without damaging the combs, and in a fraction of the time previously occupied in the draining, heating and squeezing process.
It forms a yellowishwhite deliquescent mass, which melts on heating, and at a sufficiently high temperature it yields a dark red liquid.
It forms an addition product with acrylic ester, which on heating loses nitrogen and leaves trimethylene dicarboxylic ester.
It forms colourless crystals which are soluble in water and decompose on heating, with the formation of nitrogen.
It is a brown powder which on heating in air loses sulphur and leaves a residue of the disulphide.
It is a canary-yellow powder, which becomes a dark orange on heating; the original colour is regained on cooling.
It is a colourless oily liquid of strongly acid reaction; its aqueous solution decomposes on standing and on heating it forms diethyl sulphate and sulphuric acid.
It is a greyish coloured solid, which combines very energetically with water to form the hydroxide, much heat being evolved during the combination; on heating to redness in a current of oxygen it combines with the oxygen to form the dioxide, which at higher temperatures breaks up again into the monoxide and oxygen.
It is a powerful reducing agent, and is frequently employed for this purpose in organic chemistry; thus hydroxy acids are readily reduced on heating with the concentrated acid, and nitro compounds are reduced to amino compounds, &c. It is preferable to use the acid in the presence of amorphous phosphorus, for the iodine liberated during the reduction is then utilized in forming more hydriodic acid, and consequently the original amount of acid goes much further.
It is a silvery white metal which burns on heating in air.
It is a very unstable compound, breaking up, on heating, into bromine and oxygen.
It is a white or pale yellow compound, which becomes reddish on heating.
It is a white powder, which turns pale yellow on heating, and melts at a red heat.
It is a white, infusible, very stable solid, which decomposes water on heating, giving ammonia and metaphosphoric acid, whilst alkalis give an analogous reaction.
It is also obtained by burning the metal in chlorine, by heating copper and cupric oxide with hydrochloric acid, or copper and cupric chloride with hydrochloric acid.
It is also obtained by heating para-chlorphenoldisulphonic acid with potassium hydroxide.
It is also prepared by heating trimethylamine hydrochloride.
It is an amorphous white powder; but it may also be obtained in crystals isomorphous with cassiterite by heating the amorphous form with borax to a very high temperature.
It is better, however, to effect both top and bottom heating by hot-water pipes.
It is detected by heating with ordinary alcohol and sulphuric acid, which gives rise to acetic ester or ethyl acetate, recognized by its" fragrant odour; or by heating with arsenious oxide, which forms the pungent and poisonous cacodyl oxide.
It is easily oxidized by heating with concentrated nitric acid to arsenic acid, and with concentrated sulphuric acid to arsenic trioxide; dilute nitric acid only oxidizes it to arsenious acid.
It is further purified by heating in closed vessels, but even then it still contains a certain amount of mineral matter and more or less hydrocarbons.
It is manufactured by heating pitchblende with lime, treating the resulting calcium uranate with dilute sulphuric acid, and adding sodium carbonate in excess.
It is more conveniently prepared by heating the oxide with carbon in the electric furnace.
It is not reduced to the metallic condition on heating with carbon.
It is now manufactured by heating lime and carbon in the electric furnace (see Acetylene).
It Is Readily Attainable At Any Time In A Modern Laboratory With Adequate Heating Arrangements, And Is Probably On The Whole The Most Suitable Temperature To Select.
It is reduced to metallic silver by certain metals - zinc, iron, &c. - in the presence of water, by fusion with alkaline carbonates or cyanides, by heating in a current of hydrogen, or by digestion with strong potash solution, or with potassium carbonate and grape sugar.
It is sparingly soluble in water, and on heating it yields ferric oxide and sulphur dioxide.
It is to be noted that only traces of the aromatic amines are produced by heating the halogen substituted benzenes with ammonia, unless the amino group be situated in the side chain, as in the case of benzylamine.
It is, therefore, decidedly preferable to employ " muffle-furnaces " in which the heating is performed from without, the fire-gases passing first over the arch and then under the bottom of the muffle.
It may also be prepared by heating a mixture of carbon, oxide of iron and magnesite to bright redness; and by heating a mixture of magnesium ferrocyanide and sodium carbonate, the double cyanide formed being then decomposed by heating it with metallic zinc. Electrolytic methods have entirely superseded the older methods.
It may also be prepared by heating formic and oxalic acids (or their salts) with concentrated sulphuric acid (in the case of oxalic acid, an equal volume of carbon dioxide is produced); and by heating potassium ferrocyanide with a large excess of concentrated sulphuric acid, K 4 Fe(CN) 6 -i-6H2S04+6H20=2K2S04+FeS04+3(NH4)2S04+6C0.
It may also be prepared by heating tetra-bromor tetra-chlorpyrrol with potas= sium iodide in alcoholic solution (German patent, 38423, 1886).
It may also be produced by heating an aqueous solution of di-iodosalicylic acid with excess of alkaline carbonate, by acting on dibromosalicylic acid with moist silver oxide, and by other methods.
It may be obtained crystalline by fusing the anhydrous chloride with a large excess of potassium hydrogen fluoride or by heating the amorphous variety to redness with an excess of an alkaline chloride.
It may be obtained from argyrodite by heating the mineral in a current of hydrogen; or by heating the dioxide to redness with carbon.
It may be obtained synthetically by Fittig and Tollens's method (above); by Friedel and Craft's process, devised in 1877, of acting with aluminium chloride on a mixture of benzene and methyl chloride; this reaction leads to the production of higher homologues which may, however, break down under the continued action of the aluminium chloride; or by heating the toluene carboxylic acids obtained by oxidizing the higher homologues of benzene.
It may be prepared artificially by heating copper wire to a white heat, and afterwards at a red heat, by the atmospheric oxidation of copper reduced in hydrogen, or by the slow oxidation of the metal under water.
It may be prepared by heating cuprous sulphide with sulphur, or triturating cuprous sulphide with cold strong nitric acid, or as a dark brown precipitate by treating a copper solution with sulphuretted hydrogen.
It may be prepared by passing carbon dioxide over red-hot carbon, or red-hot iron; by heating carbonates (magnesite, chalk, &c.) with zinc dust or iron; or by heating many metallic oxides with carbon.
It may be prepared by the fusion of para-toluene sulphonic acid with potash; by the action of nitrous acid on para-toluidine; or by heating para-oxyphenyl acetic acid with lime.
It may be synthetically obtained by distilling oxindole (C 8 H 8 NO) with zinc dust; by heating orthonitrocinnamic acid with potash and iron filings; by the reduction of indigo blue; by the action of sodium ethylate on orthoaminochlorstyrene; by boiling aniline with dichloracetaldehyde; by the dry distillation of ortho-tolyloxamic acid; by heating aniline with dichioracetal; by distilling a mixture of calcium formate and calcium anilidoacetate; and by heating pyruvic acid phenyl hydrazone with anhydrous zinc chloride.
It may be synthetically prepared by the fusion of cymol sulphonic acid with caustic potash; by the action of nitrous acid on 1-methyl-2-amino-4-propyl benzene; by prolonged heating of 5 parts of camphor with r part of iodine; or by heating carvol with glacial phosphoric acid.
It oxidizes on heating in air, and ignites in chlorine; on solution in mineral acids it yields ferrous and ammonium salts, hydrogen being liberated.
It reduces silver solutions in the cold and alkaline copper on heating.
It results in the alkaline fusion of many resins, and may be prepared by fusing ortho-phenolsulphonic acid, o-chlorphenol, o-bromphenol, and o-phenoldisulphonic acid with potash, or, better, by heating its methyl ether, guaiacol, C 6 H 4 (OH) (OCH 3), a constituent of beechwood tar, with hydriodic acid.
It slowly decomposes on exposure or on heating.
It sublimes, but on rapid heating decomposes into carbon dioxide and phenol.
It volatilizes slowly at ordinary temperatures, but rapidly on heating.
It was again described by Albert le Grand in the 13th century and by Raimon Lull, who prepared it by heating nitre and clay and called it "eau forte."
It was finally abandoned on account of the failure of the heating vessels.
Its salts may be obtained in some cases by heating the corresponding nitrates, but the method does not give good results.
Ladenburg, Ber., 1886, 19, p. 783); by heating the esters of nitric acid with alcoholic ammonia at 10o C. (0.
Lampadius, who obtained it by heating a mixture of charcoal and pyrites.
Lead dioxide, Pb0 2, also known as "puce oxide," occurs in nature as the mineral plattnerite, and may be most conveniently prepared by heating mixed solutions of lead acetate and bleaching powder until the original precipitate blackens.
Liebig, Ann., 1832, r, p. 199), by heating chloral with alkalis (Liebig), CC1 3 CHO + NaHO = CHC1 3 + NaHCO 2, or by heating trichloracetic acid with ammonia (J.
Lithium chloride LiC1, prepared by heating the metal in chlorine, or by dissolving the oxide or carbonate in hydrochloric acid, is exceedingly deliquescent, melts below a red heat, and is very soluble in alcohol.
Liver of sulphur or hepar sulphuris, a medicine known to the alchemists, is a mixture of various polysulphides with the sulphate and thiosulphate, in variable proportions, obtained by gently heating the carbonate with sulphur in covered vessels.
Long-continued heating with water also decomposes it slowly.
Magnesium sulphide, MgS, may be obtained, mixed with some unaltered metal and some magnesia, as a hard brown mass by heating magnesia, in sulphur vapour.
Manganese Carbide, Mn 3 C, is prepared by heating manganous oxide with sugar charcoal in an electric furnace, or by fusing manganese chloride and calcium carbide.
Manganous Sulphate, MnSO 4, is prepared by strongly heating a paste of pyrolusite and concentrated sulphuric acid until acid fumes cease to be evolved.
Manganous Sulphide, MnS, found native as manganese glance, may be obtained by heating the monoxide or carbonate in a porcelain tube in a current of carbon bisulphide vapour.
Many of the ammonium salts are made from the ammoniacal liquor of gas-works, by heating it with milk of lime and then absorbing the gas so liberated in a suitable acid.
Many of the furnaces used for this heating are in a general way like the puddling furnace shown in fig.
Many of the residences and business places of Bowling Green are heated by a privately owned central hot-water heating plant.
Martha was mixing batter while Quinn stood at the stove, heating a frying pan.
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.
Meteorological phenomena seated more directly in the atmosphere obtained early recognition; thus Hesiod, in his Works and Days, speculated on the origin of winds, ascribing them to the heating effects of the sun on the air.
Moissan (Comptes rendus, 1893, 116, p. 349; 1894, 119, p. 185) reduces the sesquioxide with carbon, in an electric furnace; the product so obtained (which contains carbon) is then strongly heated with lime, whereby most of the carbon is removed as calcium carbide, and the remainder by heating the purified product in a crucible lined with the double oxide of calcium and chromium.
Moissan (Coniptes rendus, 1896, 122, p. 1297) by heating vanadium pentoxide and carbon for a few minutes in the electric furnace.
Molybdenum disulphide, MoS 2, is found as the mineral molybdenite, and may be prepared by heating the trioxide with sulphur or sulphuretted hydrogen.
Molybdenum sesquioxide, Mo 2 O 3, a black mass insoluble in acids, is formed by heating the corresponding hydroxide in vacuo, or by digesting the trioxide with zinc and hydrochloric acid.
Molybdenum trioxide, Mo03, is prepared by oxidizing the metal or the sulphide by heating them in air, or with nitric acid.
Moreover, these secondary products cannot be successfully reduced, by further heating, to simpler hydrocarbons of any high illuminating value, and such bodies as naphthalene and anthracene have so great a stability that, when once formed, they resist any efforts again to decompose them by heat, short of the temperature which breaks them up into methane, carbon and hydrogen.
Morgan for heating billets.
Most of the polynitro compounds are not volatile, but undergo deco Imposition on heating.
Na2HPW12040 nH 2 O and Na3PW12040 nH20, are obtained by heating sodium hydrogen phosphate with a tungstate.
Natural gas derived from the Kansas fields became available for lighting and heating, and crude oil for fuel, in 1906.
Needham in 1745 had declared that heated infusions of organic matter were not deprived of living beings; Spallanzani (1777) had replied that more careful heating and other precautions prevent the appearance of organisms in the fluid.
Neilson's invention in 1828 of heating the blast, which increased the production and lessened the fuel-consumption of the furnace wonderfully.
Nevertheless, instances were adduced where the most careful heating of yolk of egg, milk, hay-infusions, &c., had failed, - the boiled infusions, &c., turning putrid and swarming with bacteria after a few hours.
Next in antiquity to hydraulic lime is Roman cement, prepared by heating an indurated marl occurring naturally in nodules.
Nitrogen is estimated by (I) Dumas' method, which consists in heating the substance with copper oxide and measuring the volume Nitrogen.
Nitrogen peroxide is also prepared by heating lead nitrate and passing the products of decomposition through a tube surrounded by a freezing mixture, when the gas liquefies.
Nor is it, when newly gathered, heating, - a defect inherent to the preserved fruit everywhere; nor does its richness, however great, bring satiety; in short it is an article of food alike pleasant and healthy."
Of other papers in which he dealt with this and kindred branches of physics may be mentioned "Observations with a Rigid Spectroscope," "Heating of a Disc by Rapid Motion in Vacuo," "Thermal Equilibrium in an Enclosure Containing Matter in Visible Motion," and "Internal Radiation in Uniaxal Crystals."
Of the dihydroterephthalic acids, the A acid is obtained by heating the dibromide of the 2 tetrahydro acid with alcoholic potash.
Of these sodium stannate, Na2Sn03, is produced industrially by heating tin with Chile saltpetre and caustic soda, or by fusing very finely powdered tinstone with caustic soda in iron vessels.
On continuing the heating, the viscosity diminishes while the colour remains the same.
On gentle heating, it is decomposed into water and nitrous oxide.
On heating in absence of air, it decomposes into the trisulphide and sulphur.
On heating it assumes a finer colour, but then turns violet and finally black; regaining, however, its original colour on cooling.
On heating it gives the diand penta-chlorides.
On heating it gives the monothio salt.
On heating it is converted into colloidal metastannic acid.
On heating they yield phosphine and leave a residue of pyrophosphate, or a mixture of metaand pyrophosphates, with a little phosphorus.
On heating to redness in a stream of hydrogen it forms a bluish mass which is probably a lower oxide of composition GaO.
On heating with an oxide or carbonate they yield a trimetallic orthophosphate, carbon dioxide being evolved in the latter case.
On heating, it is converted into the oxychloride Sb405C12 (Sb 2 O 3 =SbOC1).
On heating, the crystals lose water, swell up, and give the anhydrous sulphate, which, on further heating, gives alumina.
On its way down the cylinders the clinker meets a current of cold air and is cooled, the air being correspondingly warmed and passing on to aid in the combustion of the fuel used in heating the kiln.
On long heating the syrup is partially converted into pyrophosphoric and metaphosphoric acids, but on adding water and boiling the ortho-acid is re-formed.
On removing, washing and gently drying the metal and heating it in a glass tube, a white crystalline sublimate is formed on the cool part of the tube; under the same conditions antimony does not produce a crystalline sublimate.
On strongly heating in air it is converted into the tetroxide.
On the other hand the stability of the known oxygen compounds increases with the atomic weight, thus iodine pentoxide is, at ordinary temperatures, a well-defined crystalline solid, which is only decomposed on heating strongly, whilst chlorine monoxide, chlorine peroxide, and chlorine heptoxide are very unstable, even at ordinary temperatures, decomposing at the slightest shock.
One class, represented by gelatin, will redissolve on warming or diluting, while the other class, containing such substances as silica, albumen, and metallic, hydrosulphides, will solidify on heating or on the addition of electrolytes to form a solid "gel" which cannot be redissolved.
One practical outcome of these researches is the method now always adopted of sterilizing by a succession of gentle warmings, sufficient to kill the developed micro-organisms, instead of by one fierce heating attempting to attack the more refractory undeveloped germs of the same.
Originally prepared by heating alum, green vitriol and other sulphates, and condensing the products of distillation, sulphuric acid, or at least an impure substance containing more or less sulphur trioxide dissolved in water, received considerable attention at the hands of the alchemists.
Oxide of zinc, like most heavy metallic oxides, is easily reduced to the metallic state by heating it to redness with charcoal; pure red zinc ore may be treated directly; and the same might be done with pure calamine of any kind, because the carbon dioxide of the zinc carbonate goes off below redness and the silica of zinc silicate only retards, but does not prevent, the reducing action of the charcoal.
Oxygen may be prepared by heating mercuric oxide; by strongly heating manganese dioxide and many other peroxides; by heating the oxides of precious metals; and by heating many oxy-acids and oxy-salts to high temperatures, for example, nitric acid, sulphuric acid, nitre, lead nitrate, zinc sulphate, potassium chlorate, &c. Potassium chlorate is generally used and the reaction is accelerated and carried out at a lower temperature by previously mixing the salt with about one-third of its weight of manganese dioxide, which acts as a catalytic agent.
Oxyhalogen derivatives of chromium are known, the oxychloride, CrO 2 C1 21 resulting on heating potassium bichromate and common salt with concentrated sulphuric acid.
Paschen proved that the emission spectra of water vapour as observed in an oxyhydrogen flame, and of carbon dioxide as observed in a hydrocarbon flame may be obtained by heating aqueous vapour and carbon dioxide respectively to a few hundred degrees above the freezing point.
Peltier (1834) that heat is absorbed at the junction of two metals by passing a current through it in the same direction as the current produced by heating it, was recognized by Joule as affording a clue to the source of the energy of the current by the application of the principles of thermodynamics.
Perkin by heating crude aniline with potassium bichromate and sulphuric acid.
Phosphorus tetroxide, P204, was obtained by Thorpe and Tutton by heating the product of the limited combustion of phosphorus in vacuo as a sublimate of transparent, highly lustrous, orthorhombic crystals.
Phthalimide, C6H4(CO)2NH, is formed by heating phthalic anhydride or chloride in ammonia gas or by molecular rearrangement of ortho-cyanbenzoic acid.
Porous carbon blocks, made by strongly heating a mixture of powdered charcoal with oil, resin, &c., were introduced about a generation later, and subsequently various preparations of iron (spongy iron, magnetic oxide) found favour.
Portable boilers are convenient for heating small.
Portions can be added or taken away according to the amount of heating surface required.
Potassamide, NH 2 K, discovered by Gay-Lussac and Thenard in 1871, is obtained as an olive green or brown mass by gently heating the metal in ammonia gas, or as a white, waxy, crystalline mass when the metal is heated in a silver boat.
Potassium ferric sulphide, K2Fe2S4, obtained by heating a mixture of iron filings, sulphur and potassium carbonate, forms purple glistening crystals, which burn when heated in air.
Potassium perchlorate, Kcio 4, can be obtained by carefully heating the chlorate until it first melts and then nearly all solidifies again.
Potassium sulphide, K 2 S, was obtained by Berzelius in pale red crystals by passing hydrogen over potassium sulphate, and by Berthier as a flesh-coloured mass by heating the sulphate with carbon.
Pyrite may be prepared artificially by gently heating ferrous sulphide with sulphur, or as brassy octahedra and cubes by slowly heating an intimate mixture of ferric oxide, sulphur and salammoniac. It is insoluble in dilute acids, but dissolves in nitric acid with separation of sulphur.
Realgar occurs native in orange prisms of specific gravity 3.5; it is prepared artificially by fusing together arsenic and sulphur, but the resulting products vary somewhat in composition; it is readily fusible and sublimes unchanged, and burns on heating in a current of oxygen, forming arsenic trioxide and sulphur dioxide.
Reduction with hydriodic acid gives dibenzyl, and heating with sulphur gives tetraphenylthiophene or thionessal.
Ruthenium in bulk resembles platinum in its general appearance, and has been obtained crystalline by heating an alloy of ruthenium and tin in a current of hydrochloric acid gas.
Selenium dioxide, Se02, is prepared by burning selenium in oxygen, or by oxidizing selenium with nitric acid and heating the residue.
Several modes of heating are adopted.
Several modifications were proposed, in one of which, intended for the heating of non-conducting substances, the electrodes were passed horizontally through perforations in the upper part of the crucible walls, and the charge in the lower part of the crucible was heated by radiation.
She looked up at him, anger heating her blood again.
Sidney Young has suggested conducting the operation in a current of carbon dioxide which sweeps out the vapours as they are evolved, and also heating in a vapour bath, e.g.
Silver sulphide, Ag 2 S, constitutes the mineral argentite or silver glance, and may be obtained by heating silver with sulphur, or by precipitating a silver salt with sulphuretted hydrogen.
Similar products are also formed by heating gutta-percha which closely resembles caoutchouc in its chemical structure.
Since the advent of the incandescent mantle, the efficiency of which is dependent upon the heating power of the gas more than on its illuminating power, the manu facture of coal gas has undergone considerable modifications.
Since the demagnetizing factor was o 052, the strongest field due to the coil was about 1340; but though arrangements were pro vided for cooling the apparatus by means of o ice, great difficulty was experienced owing to heating.
Some time later Davy, by heating phosphorous acid, obtained a phosphoretted hydrogen which was not spontaneously inflammable.
Stannic sulphide, SnS 2, is obtained by heating a mixture of tin (or, better, tin amalgam), sulphur and sal-ammoniac in proper proportions in the beautiful form of aurum musivum (mosaic gold) - a solid consisting of golden yellow, metallic lustrous scales, and used chiefly as a yellow "bronze" for plaster-of-Paris statuettes, &c. The yellow precipitate of stannic sulphide obtained by adding sulphuretted hydrogen to a stannic solution readily dissolves in solutions of the alkaline sulphides to form thiostannates of the formula M 2 SnS 31 the free acid, H2SnS3, may be obtained as an almost black powder by drying the yellow precipitate formed when hydrochloric acid is added to a solution of a thiostannate.
Stannous Chloride, SnC1 2, can only be obtained pure by heating pure tin in a current of pure dry hydrochloric acid gas.
Stannous sulphide, SnS, is obtained as a lead-grey mass by heating tin with sulphur, and as a brown precipitate by adding sulphuretted hydrogen to a stannous solution; this is soluble in ammonium polysulphide, and dries to a black powder.
Starting with a solid hydrocarbon of definite composition, it would be theoretically possible to decompose it entirely into carbon, hydrogen, ethylene and methane, and, by rapidly removing these from the heating zone before any secondary actions took place, to prevent formation of tar.
Stirring Is Effected By Causing The Water To Circulate Spirally Round The Bulbs Of The Thermometers And The Heating Conductor As Indicated In The Figure.
Strong heating decomposes the majority of the iodides.
Strontium carbide, SrC2, is obtained by heating strontium carbonate with carbon in the electric furnace.
Succinic anhydride, C 2 H 4 (CO) 2 0, is obtained by heating the acid or its sodium salt with acetic anhydride; by the action of acetyl chloride on the barium salt; by distilling a mixture of succinic acid and succinyl chloride, or by heating succinyl chloride with anhydrous oxalic acid.
Sulphates may be detected by heating the salt mixed with sodium carbonate on charcoal in the reducing flame of the blowpipe; sodium sulphide is thus formed, and may be identified by the black stain produced if the mass be transferred to a silver coin and then moistened.
Sulphur is detected by heating the substance with sodium, dissolving the product in water, and adding sodium nitroprusside; a bluish-violet coloration indicates sulphur.
Sulphuric and hydrochloric acids have little or no action upon it at ordinary temperatures, even when in a fine state of division; but on heating, copper sulphate and sulphur dioxide are formed in the first case, and cuprous chloride and hydrogen in the second.
Tafel, Ber., 1886, 19, p. 1924), by distilling the amido-acids with lime, by heating phenols with zinc chloride ammonia (V.
Tantalum pentachloride, TaC1 5, is obtained as light yellow needles by heating a mixture of the pentoxide and carbon in a current of chlorine.
Tantalum pentoxide, Ta205, is a white amorphous infusible powder, or it may be crystallized by strongly heating, or by fusing with boron trioxide or microcosmic salt.
The -y-diketones are characterized by the readiness with which they yield furfurane, pyrrol and thiophene derivatives, the furfurane derivatives being formed by heating the ketones with a dehydrating agent, the thiophenes, by heating with phosphorus pentasulphide, and the pyrrols by the action of alcoholic ammonia or amines.
The "browse," after removal of the "grey" slag, is reintroduced, ore added, and, after a quarter of an hour's heating, the mass again placed on the work-stone, &c.
The "D" form is mostly adopted owing to its power of retaining its shape after long exposure to heat, and the large amount of heating surface it presents at its base.
The 2.3 derivatives are somewhat unstable compounds, since on heating they readily give up two hydrogen atoms. Tetrahydropyrazines of the 1.2.
The 2' acid is formed when phthalic acid is reduced in the cold by sodium amalgam or by heating the A 2 ' 4 and A 3 " acids with caustic soda.
The A l -' 4 acid is obtained as its anhydride by heating A 2.4 dihydrophthalic anhydride with acetic anhydride.
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.
The acid is formed by dissolving phosphorus pentoxide in cold water, or by strongly heating orthophosphoric acid.
The acid on heating loses CO 2 and gives cyclo-hexanedione-I.4.
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.
The alkyl derivatives may be obtained by heating phenol with one molecular proportion of a caustic alkali and of an alkyl iodide.
The amount of methyl alcohol present in wood spirit is determined by converting it into methyl iodide by acting with phosphorus iodide; and the acetone by converting it into iodoform by boiling with an alkaline solution of iodine in potassium iodide; ethyl alcohol is detected by giving acetylene on heating with concentrated sulphuric acid, methyl alcohol, !under the same circumstances, giving methyl ether.
The ancient records of China and Japan are said to contain many allusions to the use of natural gas for lighting and heating.
The anhydrous chloride is formed by heating strontium or its monoxide in chlorine, or by heating the hydrated chloride in a current of hydrochloric acid gas.
The anhydrous nitrate, obtained by heating the crystallized salt, is very phosphorescent, and constitutes "Baldwin's phosphorus."
The anhydrous oxide is with difficulty soluble even in hydrofluoric acid; but a mixture of two parts of concentrated sulphuric acid and one of water dissolves it on continued heating as the sulphate, Zr(S04)2.
The anhydrous salt is obtained by heating, or by adding concentrated sulphuric acid to a solution.
The anhydrous salt may be prepared by heating a saturated solution of the hydrated salt.
The aqueous solution of this salt liberates carbon dioxide on exposure to air or on heating, and becomes alkaline in reaction.
The blue colour, which disappears on heating or dissolving the salt, has been variously ascribed to the presence of sodium subchloride, sodium, sulphur or of a certain compound of iron, or again to the existence of minute cavities with parallel walls.
The borate, Pb 2 B 6 0 1 u 4H20, is obtained as a white precipitate by adding borax to a lead salt; this on heating with strong ammonia gives PbB2044H2.
The bottle is carefully cleansed by washing with soda, hydrochloric acid and distilled water, and then dried by heating in an air bath or by blowing in warm air.
The bromide and iodide are formed in a similar manner by heating the metal in gaseous hydrobromic or hydriodic acids.
The change from one state to the other takes place at a higher temperature on heating than on cooling.
The chloride is very hygroscopic. By heating in hydrogen it yields the trichloride, UC1 3, and by direct combination with chlorine the pentachloride, UC1 5.
The coefficient of heating of a calorimeter when it is below the temperature of its surroundings is seldom, if ever, the same as the coefficient of cooling at the higher temperature, since the convection currents, which do most of the heating or cooling, are rarely symmetrical in the two cases, and moreover, the duration of the two stages is seldom the same.
The commercial salt is known as salvolatile or salt of hartshorn and was formerly obtained by the dry distillation of nitrogenous organic matter such as hair, horn, decomposed urine, &c., but is now obtained by heating a mixture of sal-ammoniac, or ammonium sulphate and chalk, to redness in iron retorts, the vapours being condensed in leaden receivers.
The conversion of silver into the sulphide may be effected by heating with antimony sulphide, litharge and sulphur, pyrites, or with sulphur alone.
The d-form is found as a methyl ether in pirate (from the juice of Pinus lambertina, and of caoutchouc from Mateza roritina of Madagascar), from which it may be obtained by heating with hydriodic acid.
The details of the plant - the material and fittings of the still, the manner of heating, the form of the condensing plant, receivers, &c. - have to be determined for each substance to be distilled in order to work with the maximum economy.
The dichloride, WC1 2, is an amorphous grey powder obtained by reducing the hexachloride at a high temperature in hydrogen, or, better, by heating the tetrachloride in a current of carbon dioxide.
The dioxide, Ru02, is formed by heating sulphate, or by heating the metal in a current of oxygen.
The distillation is then effected by heating to dull redness.
The earliest form of testing instrument employed for this purpose was that of Giuseppe Tagliabue of New York, which consists of a glass cup placed in a copper water bath heated by a spirit lamp. The cup is filled with the oil to be tested, a thermometer placed in it and heat applied, the temperatures being noted at which, on passing a lighted splinter of wood over the surface of the oil, a flash occurs, and after further heating, the oil ignites.
The experiment proves only the transparency of the gases experimented upon, and this is confirmed by the fact that bodies like bromine and iodine give on heating an emission spectrum corresponding to the absorption spectrum seen at ordinary temperatures.
The external heat-loss was eliminated by comparing observations taken at the same mean temperatures during heating and during cooling, assuming that the rate of loss of heat f(S) would be the same in the two cases.
The first is prepared by heating red phosphorus with finely powdered sulphur in a tube sealed at one end and filled with carbon dioxide.
The first process consists essentially in heating the alloy with salt and brickdust; the latter absorbs the chloride formed, while the gold is recovered by washing.
The first step in the synthetical production of alizarin was the discovery in 1868 of C. Graebe and C. Liebermann that on heating with zinc dust, alizarin was converted into anthracene.
The first successful idea of using electricity depended on the enormous heating powers of the arc. The infusibility of alumina was no longer prohibitive, for the molten oxide is easily reduced by carbon.
The greatest care is taken that no steel is left in a brittle condition by heating and cooling without proper annealing.
The halogens may be estimated by ignition with quicklime, or by heating with nitric acid and silver nitrate in a sealed tube.
The haloid esters of the paraffin alcohols formed by heating the alcohols with the halogen acids are the monohaloid derivatives of the paraffins, and are more conveniently prepared by the action of the phosphorous haloid on the alcohol.
The hardening of steel consists in first transforming it into austenite by heating it up into region 4 of fig.
The heating and ventilating arrangements are much the same as in the lean-to, only the top sashes which open are on the back slope, and therefore do not interfere so much with the vines on the front slope.
The heating at the surfaces, the variations in their smoothness, and the variations of the lubrication make continuously variable, and necessitate frequent adjustment of W or of the nuts.
The heating is continued for 4 to 12 hours according to the amount of silver present; the end of the reaction is known by the absence of any hissing.
The heating of the latter causes great differences of pressure, which in turn set up changes of atmospheric circulation.
The heating vessel could be maintained at a steady temperature by high-pressure steam.
The hexachloride, Si 2 C1 61 is formed when silicon chloride vapour is passed over strongly heated silicon; by the action of chlorine on the corresponding iodocompound, or by heating the iodo-compound with mercuric chloride (C. Friedel, Comptes rendus, 18 7 1, 73, P. 497).
The hexachloride, WC1 6, is obtained by heating the metal in a current of dry chlorine in the absence of oxygen or moisture, otherwise some oxychloride is formed; a sublimate of dark violet crystals appear at first, but as the hexachloride increases in quantity it collects as a very dark red liquid.
The hydrated salt loses water on heating, and partially decomposes into hydrochloric acid and magnesium oxychlorides.
The hydride, SrH 2, was obtained by Guntz on heating strontium amalgam in a current of hydrogen.
The hydrosulphide, KHS, was obtained by Gay-Lussac on heating the metal in sulphuretted hydrogen, and by Berzelius on acting with sulphuretted hydrogen on potassium carbonate at a dull red heat.
The instrument exhibited by Thompson would, without undue heating, take a current of 30 amperes, which was sufficient to produce a magnetizing force of woo units.
The Kassner process for the manufacture of oxygen depends upon the formation of calcium plumbate, Ca2Pb04, by heating a mixture of lime and litharge in a current of air, decomposing this substance into calcium carbonate and lead dioxide by heating in a current of carbon dioxide, and then decomposing these compounds with the evolution of carbon dioxide and oxygen by raising the temperature.
The latex, which is usually coagulated by standing or by heating, is obtained from incisions in the bark of the tree.
The lining of the converter is made of 90% of the mixture of lime and magnesia which results from calcining dolomite, (Ca,Mg)CO i, at a very high temperature, and 10% of coal tar freed from its water by heating.
The loose material may, and in an arid region does, consist only of portions of the higher parts of the surface detached by the expansion and contraction produced by heating and cooling due to radiation.
The majority of the metallic chlorides are solids (stannic chloride, titanic chloride and antimony pentachloride are liquids) which readily volatilize on heating.
The metal is quite permanent in dry air, but in moist air it becomes coated with a superficial layer of the oxide; it burns on heating to redness, forming a brown coloured oxide; and is readily soluble in mineral acids with formation of the corresponding salts.
The metal was obtained by Berzelius as an iron-grey powder by heating potassium zirconofluoride with metallic potassium.
The mixed secondary amines are prepared by the action of alkyl iodides on the primary amines, or by heating salts of the primary amine with alcohols under pressure.
The mode of heating varies with the substance to be distilled.
The modern practice consists in heating the perfectly fresh, cleaned livers by steam to a temperature above that of boiling water, or, in more recent practice, to a lower temperature, the livers being kept as far as possible from contact with air.
The monovalent iodine, for instance, is transformed by heating into an allotropic form, corresponding to the formula I, whereas ordinary iodine answers to I 2.
The monoxychloride, WOC14, is obtained as red acicular crystals by heating the oxide or dioxychloride in a current of the vapour of the hexachloride, or from the trioxide and phosphorus pentachloride.
The most important is the normal salt, Na 4 P 2 0 7, which is readily obtained by heating disodium orthophosphate, Na 2 HPO 4.
The municipality has natural gas for heating, lighting and manufacturing.
The natural effect of the heating of the air in summer and the cooling of the air in winter by contact with the land is largely masked in England on account of the strength of the prevailing south-westerly wind carrying oceanic influence into the heart of the country.
The next great improvement in blast-furnace practice came in 1811, when Aubertot in France used for heating steel the furnace gases rich in carbonic oxide which till then had been allowed to burn uselessly at the top of the blast furnace.
The oil for ink-making is prepared by heating it in an iron pot up to the point where it either takes fire spontaneously or can be ignited with any flaming substance.
The ordinary commercial arsenic is either the naturally occurring form, which is, however, more or less contaminated with other metals, or is the product obtained by heating arsenical pyrites, out of contact with air, in earthenware retorts which are fitted with a roll of sheet iron at the mouth, and an earthenware receiver.
The perfectly pure metal may be prepared by heating the oxide or oxalate in a current of hydrogen; when obtained at a low temperature it is a black powder which oxidizes in air with incandescence; produced at higher temperatures the metal is not pyrophoric. Peligot obtained it as minute tetragonal octahedra and cubes by reducing ferrous chloride in hydrogen.
The peroxide, K204, discovered by Gay-Lussac and Thenard, is obtained by heating the metal in an excess of slightly moist air or oxygen.
The phosphide obtained by heating cupric phosphate, Cu 2 H 2 P 2 O 81 in hydrogen, when mixed with potassium and cuprous sulphides or levigated coke, constitutes " Abel's fuse," which is used as a primer.
The phosphorescence of the sulphide obtained by heating the thiosulphate is much increased by adding uranium, bismuth, or thorium before ignition pr.
The principles which govern the preparation and setting of the other class of calcium sulphate cements, that is, cements of the Keene class, are not fully understood, but there is a fair amount of knowledge on the subject, both empirical and scientific. The essential difference between the setting of Keene's cement and that of plaster of Paris is that the former takes place much more slowly, occupying hours instead of minutes, and the considerable heating and expansion which characterize the setting of plaster of Paris are much less marked.
The process consists in heating yellow phosphorus in iron pots provided with air-tight lids, which,.
The process is tedious, the resulting fibre is brown in colour, and it is said to be peculiarly liable to undergo heating (probably owing to the soft heavy quality of the flax) if exposed to moisture and kept close packed with little access of air.
The reaction proceeds better on heating the solution.
The rubber is obtained by incising the stems of the vines and coagulating the latex by exposure, by admixture with acid vegetable juices or by heating.
The salts of hydrochloric acid, known as chlorides, can, in most cases, be prepared by dissolving either the metal, its hydroxide, oxide, or carbonate in the acid; or by heating the metal in a current of chlorine, or by precipitation.
The same may be said of charcoal, both for heating and mechanical purposes.
The second, P4S7, is obtained by heating a mixture of red phosphorus and sulphur in the proportions given by P4S7+5% P4S3, and crystallizing from carbon disulphide in which P 4 S 3 is readily soluble.
The secondary amines may be of two types-namely,the purely aromatic amines, and the mixed secondary amines, which contain an aromatic residue and an alkyl group. The purely aromatic amines result upon heating the primary amines with their hydrochlorides, and, in some cases, by heating a phenol with a primary amine and anhydrous zinc chloride.
The sesquioxide, Ce 2 O 3, is obtained by heating the carbonate in a current of hydrogen.
The sesquioxide, Os203, results on heating osmium with an excess of the tetroxide.
The simple "syrup" of the British Pharmacopoeia is prepared by adding 1000 grams (or 5 lb) of refined sugar to 500 cubic centimetres (or two pints) of boiling distilled water, heating until it is dissolved and subsequently adding boiling distilled water until the weight of the whole is 1500 grams (or 71 lb).
The sodium salt on heating with phosphorus trisulphide yields methylthiophen.
The solution absorbs nitric oxide to form a dark brown solution, which loses the gas on heating or by placing in a vacuum.
The staff, excluding purely scientific departments, costs about £6000 per annum; gardening department, about £1500 per annum; maintenance of buildings, enclosures, paths and so forth, about £4000 per annum; provisions for animals, about £5000 per annum; litter, water, heating and general menagerie expenses about £3000 per annum.
The sulphate, Zr(S04)2, is a white mass obtained by dissolving the oxide or hydroxide in sulphuric acid, evaporating and heating the mass to nearly a red heat.
The terpenes all possess a characteristic odour and are fairly stable to alkalis, but are easily decomposed by acids or by heating to a sufficiently high temperature.
The trans A 4 acid is formed by heating the cis-acid with hydrochloric acid under pressure.
The trans-acid is a racemic compound, which on heating with acetyl chloride gives the anhydride of the cis-acid.
The trans-acid is produced on heating pyrazolin-4.5-dicarboxylic ester, or by the action of alcoholic potash on a-bromglutaric ester.
The trichloride, IC1 31 results from the action of excess of chlorine on iodine, or from iodic acid and hydrochloric acid, or by heating iodine pentoxide with phosphorus pentachloride.
The water-gas itself is made for 7 minutes, and has an average composition of 3.3% carbon dioxide, 44% carbon monoxide, o 4% methane, 48.6% hydrogen, 3.7% nitrogen, and a heating value of 2970 calories per cub.
The whole mass dissolves on heating, and the anthracene crystallizes out on cooling.
The wide heated plains of the Sahara, and in a lesser degree the corresponding zone of the Kalahari in the south, have an exceedingly scanty rainfall, the winds which blow over them from the ocean losing part of their moisture as they pass over the outer highlands, and becoming constantly drier owing to the heating effects of the burning soil of the interior; while the scarcity of mountain ranges in the more central parts likewise tends to prevent condensation.
The, chief uncertainty in applying this method appears to have arisen from variations of temperature at different parts of the surface, due to inequalities in the heating or cooling effect of the stream of water flowing over the surfaces.
Thenard and is best obtained by heating a mixture of the trioxide and fluorspar with concentrated sulphuric acid.
Thenard in 1808 by heating boron trioxide with potassium, in an iron tube.
Thence they are sucked out by the chimney-draught through the left-hand ports, down through the uptakes and regenerators, here again meeting ands heating the loose mass of " regenerator " brickwork, and finally escape by the chimney-flue 0.
There A is the externallyfired heating vessel, the lower part of which contains hot air which is taking in heat from the furnace beneath.
There are other forms of shaft kiln, such as the Schneider, in which there is a burning zone, a heating and cooling zone as in the Dietzsch, but no horizontal stage, the whole shaft being in the same vertical plane.
There are polymers which have hardly any inter-relations other than identity in composition; on the other hand, there are others which are related by the possibility of mutual transformation; examples of this kind are cyanic acid (Cnoh) and cyanuric acid (Cnoh) 3, the latter being a solid which readily transforms into the former on heating as an easily condensable vapour; the reverse transformation may also be realized; and the polymers methylene oxide (CH 2 O) and trioxymethylene (CH20)3.
These are made by heating a circular-ridged earthen plate over a slow fire, and spreading the petals, a few at a time, over its surface.
These esters are readily hydrolysed and yield the monoand di-alkylimalonic acids which, on heating, are readily decomposed, with evolution of carbon dioxide and the formation of monoand di-alkyl acetic acids.
These isomers may frequently be distinguished by the facts that the cis-acids yield anhydrides more readily than the trans-acids, and are generally converted into the trans-acids on heating with hydrochloric acid.
These substances condense to form tetra-aminotriphenylmethane, which, on heating with acids, loses ammonia and yields diaminodihydrophenylacridine, from which benzoflavin is obtained by oxidation.
These three acids yield on heating phenol, identical with the substance started with, and since in the three oxybenzoic acids the hydroxyl groups must occupy positions other than I, it follows that four hydrogen atoms are equal in value.
These two things are done simultaneously by heating and melting the ore in contact with coke, charcoal or anthracite, in the iron blast furnace, from which issue intermittently two molten streams, the iron now deoxidized and incidentally carburized by the fuel with which it has been in contact, and the mineral matter, now called " slag."
They are all decomposed on heating, with evolution of oxygen; and in contact with concentrated sulphuric acid with liberation of chlorine peroxide.
They are decomposed on heating, with liberation of oxygen, in some cases leaving a residue of iodide and in others a residue of oxide of the metal, with liberation of iodine as well as of oxygen.
They are made by heating to a high temperature an intimate mixture of a calcareous substance and an argillaceous substance.
They are not decomposed by boiling alkalis, but on heating with hydriodic acid they split into their components.
They are of a reddish colour and usually crystallize well; on heating with concentrated acids are usually transformed into the purpureo-salts.
They are strong oxidizing agents and yield alkaline solutions which readily evolve oxygen on heating.
They may also be prepared by heating the alkyl halides with silver oxide.
They may be obtained by heating a monometallic orthophosphate of a fixed base, or a dimetallic orthophosphate of one fixed and one volatile base, e.g.
They may be prepared by the action of concentrated sulphuric acid on the alcohols, alkyl sulphuric acids being first formed, which yield ethers on heating with alcohols.
They readily decompose on heating, and are easily hydrolysed by alkalies; they possess a somewhat more acid character than.
This action must be promoted by heating the mixture, but even then nothing like all of the hydrochloric acid employed is made to act as above, because the attack on the manganese ore requires a certain minimum concentration of the acid.
This board is required to visit each of the institutions at least once a year to ascertain its condition and needs, and all proposed appropriations for their support, plans of buildings, proposed systems of sewerage, ventilation and heating must be submitted to it.
This compound occurs in nature as bismuth ochre, and may be prepared artificially by oxidizing the metal at a red heat, or by heating the carbonate, nitrate or hydrate.
This heating was formerly done by burning part of the gases, after their escape from the furnace top, in a large combustion chamber, around a series of cast iron pipes through which the blast passed on its way from the blowing engine to the tuyeres.
This instrument is so constructed that the higher temperature needed can be readily applied, and it is fitted with a stirrer to equalize the heating of the contents of the oil-cup.
This lasts into February, when the northerly current begins to lose strength, and the gradual heating of the land produces local sea breezes from the gulf along the coast-line.
This may consist of a steam injector by means of which air is made to bubble through the liquid, which produces both the required agitation and the heating, and at the same time oxidizes at least part of the sulphides; but this method of agitation causes a great waste of steam and at the same time a further dilution of the liquor.
This oxide is produced by heating lead in contact with air and removing the film of oxide as formed.
This process consists in heating a mixture ofcommercial FIG.
This regenerative heating is similar in principle and effect to that obtained by means of the shaft and ring kilns described above.
This substance dissolves slowly in water, forming arsenic acid; by heating to redness it decomposes into arsenic and oxygen.
This sulphide is then by further heating converted into the oxide and finally reduced to the state of metal by ignition with carbon in clay crucibles.
This type of house is also very suitable for greenhouse plants, but would not need so much heating apparatus.
Thisas, which is made for 10 or I I minutes, contains from 23 to 32% carbon monoxide, 7 to I 5% carbon dioxide, 2 to 3% hydrogen, a little methane, 64 to 66% nitrogen, and has a heating value of 950 calories per cub.
Thorium chloride, ThC1 4, is obtained as white shining crystals by heating a mixture of carbon and thoria in a current of chlorine.
Thorpe and Laurie converted potassium auribromide into a mixture of metallic gold and potassium bromide by careful heating.
Those derived from monobasic acids, obtained by the action of acid chlorides or anhydrides on urea, decompose on heating and do not form salts.
Three oxides of barium are known, namely, the monoxide, BaO, the dioxide, Ba02, and a suboxide, obtained by heating Ba0 with magnesium in a vacuum to 110o (Guntz, loc. cit., 1906, p. 359).
Thus by heating spirits of salt he obtained "marine acid air" (hydrochloric acid gas), and he was able to collect it because he happened to use mercury, instead of water, in his pneumatic trough.
Thus in the Westphalian pig and scrap practice, scrap usually forms 75 or even 80% of the charge, and pig only from 20 to 25%, indeed only enough to supply the carbon inevitably burnt out in melting the charge and heating it up to a proper casting temperature; and here the charge lasts only about 6 hours.
Thus the furnace may be said to have four zones, those of (1) deoxidation, (2) heating, (3) melting, and (4) collecting, though of course the heating is really going on in all four of them.
Thus the necessary slowness of the heating up of the molten charge would compel us to make the removal of the carbon slow, even if this slowness were not already forced on us by the danger of having the charge froth so much as to run out of the furnace.
Ti 3 N 4 is a copper-coloured powder obtained by heating the ammonio-chloride TiC1 4.4NH 3 in ammonia.
TiN 2 is a dark blue powder obtained when the oxide is ignited in an atmosphere of ammonia; while TiN is obtained as a bronze yellow mass as hard as the diamond by heating the oxide in an atmosphere of nitrogen in the electric furnace.
Titanium monoxide, TiO, is obtained as black prismatic crystals by heating the dioxide in the electric furnace, or with magnesium powder.
Titanium sesquioxide, Ti 2 O 3, is formed by heating the dioxide in hydrogen.
To bring them to a temperature suitable for rolling, these ingots must be set in heating or soaking furnaces (§ 125), and this should be done as soon as possible after they are cast, both to lessen the loss of their initial heat, and to make way for the next succeeding lot of ingots, a matter of great importance, because the charges of steel follow each other at such very brief intervals.
To produce plaster of Paris European practice consists in baking the mineral in ovens, and in America in heating it in kettles.
Tungsten may be prepared from wolfram by heating the powdered ore with sodium carbonate, extracting the sodium carbonate with water, filtering and adding an acid to precipitate tungstic acid, H 2 W0 4.
Uranous chloride, UC14, was first prepared by Peligot by heating an intimate mixture of the green oxide and charcoal to redness in a current of dry chlorine; it is obtained as sublimate of black-green metallic-looking octahedra.
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.
Ventilation may be produced by heating the air of the mine, as for example, by constructing a ventilating furnace at the bottom of an air shaft.
Very soon after this, in 1832, the work of heating the blast was done by means of the waste gases, at Wasseralfingen in Bavaria.
Wahl [German patent 70773 (1893)] prepare a 97% manganese from pyrolusite by heating it with 30% sulphuric acid, the product being then converted into manganous oxide by heating in a current of reducing gas at a dull red heat, cooled in a reducing atmosphere, and finally reduced by heating with granulated aluminium in a magnesia crucible with lime and fluorspar as a flux.
Water decomposes it, giving a basic salt, Bi 2 (SO 4)(OH) i which on heating gives (BiO) 2 SO 4.
When a concentrated solution of auric chloride is treated with caustic potash, a brown precipitate of auric hydrate, Au(OH) 3, is obtained, which, on heating, loses water to form auryl hydrate, AuO(OH), and auric oxide, Au 2 0 3.
When concentrated the solution is nearly black, and on heating it yields a yellow solution of potassium ferrite, oxygen being evolved.
When cyanogen is prepared by heating mercuric cyanide, a residue known as para-cyanogen, (CN)x, is left; this is to be regarded as a polymer of cyanogen.
When heated in a current of hydrogen it is transformed into the colourless disulphide, whilst if the heating be carried out in a current of nitrogen it yields the trisulphide, Rb 2 S 3 H 2 0.
When heated they liquefy; and if the heating be continued, the water of crystallization is driven off, the salt froths and^swells, and at last an amorphous powder remains.
When precipitated from solutions it forms red tetragonal crystals, which, on careful heating, give a yellow rhombic form, also obtained by crystallization from the fused substance, or by sublimation.
When prolonged heating is required at very high temperatures it is found necessary to line the furnace-cavity with alternate layers of magnesia and carbon, taking care that the lamina next to the lime is of magnesia; if this were not done the lime in contact with the carbon crucible would form calcium carbide and would slag down, but magnesia does not yield a carbide in this way.
When the converter is full the pressure is raised somewhat, and the heating continued until the conversion is complete.
When the passage of an electric current through a substance is accompanied by definite chemical changes which are independent of the heating effects of the current, the process is known as electrolysis, and the substance is called an electrolyte.
While you're heating that stuff up, I think I'll go out and lock Princess in the barn.
With concentrated nitric acid, in the presence of cold concentrated sulphuric acid, it yields trinitro-resorcin (styphnic acid), which forms yellow crystals, exploding violently on rapid heating.
With high current-density, heating the solution tended to increase the proportion of chlorate to hypochlorite, but as the proportion of water decomposed is then higher, the amount of chlorine produced must be less and the total chlorine efficiency lower.
With the juice of some canes considerable difficulty is encountered in keeping the heating surfaces of the evaporators clean and free from incrustations, and cleaning by the use of acid has to be resorted to.
Wohler, Ann., 1856, 97, p. 266; 1857, 102, p. 382); by heating silica with magnesium in the presence of zinc (L.
Zirconium fluoride, ZrF4, is obtained as glittering monoclinic tables (with 3H 2 0) by heating zirconia with acid ammonium fluoride.