Heated Sentence Examples
He left the basement and entered the heated first floor.
Iridium sesquichloride, IrC1 31 is obtained when one of the corresponding double chlorides is heated with concentrated sulphuric acid, the mixture being then thrown into water.
His gaze flared with heated interest.
They exchanged a heated look so intense Kiera blushed.
Iridium sesquioxide, Ir 2 0 3, is obtained when potassium iridium chloride is heated with sodium or potassium carbonates, in a stream of carbon dioxide.Advertisement
His blood heated at her familiar scent.
It may be obtained in the spongy form by igniting iridium ammonium chloride, and this variety of the metal readily oxidizes when heated in air.
While we were sympathetic to dad, we decided after heated discussion simply tip what we learned.
A closed stove acts mainly by convection; though when heated to a high temperature it gives out radiant heat.
Arguments concerning contact with tip lines became heated as well.Advertisement
Therefore in a room with an open fire the air is, as a rule, less heated than the walls.
The sounds of heated discussion made her look toward the river.
He was heated and huge at her back.
Cadmium salts can be recognized by the brown incrustation which is formed when they are heated on charcoal in the oxidizing flame of the blowpipe; and also by the yellow precipitate formed when sulphuretted hydrogen is passed though their acidified solutions.
The pieces are carefully heated with exclusion of air and then compressed into a uniform mass by intense hydraulic pressure; the softened amber being forced through holes in a metal plate.Advertisement
Sulphur is present to the extent of more than i %, whence the smell of suiphuretted hydrogen when the resin is heated.
When heated with aniline it yields phenol and acetanilide.
If the viscous variety be rapidly cooled, or the more highly heated mass be poured into water, an elastic substance is obtained, termed plastic sulphur.
It is decomposed by the influence of strong light or when strongly heated.
It is decomposed readily into sulphur trioxide and oxygen when heated.Advertisement
Not that the regime in Russia had become in any true sense constitutional, far less parliamentary; but the " unlimited autocracy " had given place to a " self-limited autocracy," whether permanently so limited, or only at the discretion of the autocrat, remaining a subject of heated controversy between conflicting parties in the state.
In that most largely used, known as " creosoting," dead oil of tar, to the amount of some 3 gallons per sleeper, is forced into the wood under pressure, or is sucked in by vacuum, both the timber and the oil being heated.
These in their simplest form are cans filled with water, which is heated by immersing them in a vessel containing boiling water.
In some cases, however, they are filled with fused acetate of soda; this salt is solid when cold, but when the can containing it is heated by immersion in hot water it liquefies, and in the process absorbs heat which is given out again on the change of state back to solid.
On electric railways the trains are heated by electric heaters.Advertisement
We might at first suppose that the sun was really an intensely heated body radiating out its heat as does white-hot iron, but this explanation cannot be admitted, for there is no historical evidence that the sun is growing colder.
The great summer heat, by expanding the air upwards, disturbs the level of the planes of equal pressure, and causes an outflow of the upper strata from the heated area.
The heated body of air carried from the Indian Ocean over southern Asia by the south-west monsoon comes up highly charged with watery vapour, and hence in a condition to release a large body of water as rain upon the land, whenever it is brought into circumstances which reduce its temperature in a notable degree.
Joffrin was only admitted to the Chamber after a heated discussion, and continued to be attacked by the nationalists.
The climate of Bellary is characterized by extreme dryness, due to the passing of the air over a great extent of heated plains, and it has a smaller rainfall than any other district in south India.
This view is supported by the fact that petroleum is found on the Sardinian and Swedish coasts as a product of the decomposition of seaweed, heated only by the sun, and under atmospheric pressure.
The stills were formerly completely bricked in, so that the vapours should be kept fully heated until they escaped to the condenser, but since the introduction of the " cracking process," the upper part has usually been left exposed to the air.
This may be brought about by a distillation under pressure, or by allowing the condensed distillate to fall into the highly heated residue in the still.
In the American petroleum refineries it is found that sufficient cracking can be produced by slow distillation in stills of which the upper part is sufficiently cool to allow of the condensation of the vapours of the less volatile hydrocarbons, the condensed liquid thus falling back into the heated body of oil.
The steam is superheated and may thus be heated to any desired temperature without increase of pressure, which would be liable to damage the still.
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.
Heated with sulphuric acid and with nitric acid it is oxidized to boric acid, whilst on fusion with alkaline carbonates and hydroxides it gives a borate of the alkali metal.
The expansion of the working wire when it is heated will then increase or create a sag in it owing to its increase in FIG.
In order that this may take place, the heated wire must be flexible and must therefore be a single fine wire or a bundle of fine wires.
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.
The process of manufacturing soaps by boiling fatty acids with caustic alkalis or sodium carbonate came into practice with the development of the manufacture of candles by saponifying fats, for it provided a means whereby the oleic acid, which is valueless for candle making, could be worked up. The combination is effected in open vats heated by a steam coil and provided with a stirring appliance; if soda ash be used it is necessary to guard against boiling over.
The soap is now milled in the form of ribbons with the perfume and colouring matter, and the resulting strips are welded into bars by forcing through a heated nozzle.
It is a good solvent for sulphur, phosphorus, wax, iodine, &c. It dissociates when heated to a sufficiently high temperature.
Potassium, when heated, burns in the vapour of carbon bisulphide, forming potassium sulphide and liberating carbon.
A mixture of carbon bisulphide vapour and sulphuretted hydrogen, when passed over heated copper, gives, amongst other products, some methane.
It fuses easily in the electric arc. It oxidizes superficially when heated, but fairly rapidly when ignited in an oxidizing blowpipe flame, forming a black smoke of the oxide.
It is insoluble in acids and decomposes when heated to a sufficiently high temperature.
An oxide of composition Ru 4 0 9 is obtained as a black hydrated powder when the peroxide is heated with water for some time.
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.
If silica be present, it gives the iron bead when heated with a little ferric oxide; if tin is present there is no change.
Carbon is detected by the formation of carbon dioxide, which turns lime-water milky, and hydrogen by the formation of water, which condenses on the tube, when the substance is heated with copper oxide.
Nitrogen may be detected by the evolution of ammonia when the substance is heated with soda-lime.
The substance is heated with metallic sodium or potassium (in excess if sulphur be present) to redness, the residue treated with water, filtered, and ferrous sulphate, ferric chloride and hydrochloric acid added.
If all the connexions are sound, the copper oxide is gradually heated from the end a, the gas-jets under the spiral d are lighted, and a slow current of oxygen is passed through the tube.
The magnesite (a) serves for the generation of carbon dioxide which clears the tube of air before the compound (mixed with fine copper oxide (b)) is burned, and afterwards sweeps the liberated nitrogen into the receiving vessel (e), which contains a strong potash solution; c is coarse copper oxide; and d a reduced copper gauze spiral, heated in order to decompose any nitrogen oxides.
The reverse series of transformations occurs when this final modification is heated.
The name of "Clemency Canning," which was applied to him during the heated animosities of the moment, has since become a title of honour.
Manasse (German patent 73,279) prepared an intimate mixture of phenol and potassium carbonate, which is then heated in a closed vessel with carbon dioxide, best at 130 -160 C. The Chemische Fabrik vorm.
When heated in air for many hours it decomposes, yielding carbon dioxide, phenol and xanthone.
The product is at first white, but soon turns green ("green ultramarine") when it is mixed with sulphur and heated.
Saturated steam is steam in contact with liquid water at a temperature which is the boiling point of the water and condensing point of the steam; superheated steam is steam out of contact with water heated above this temperature.
This may be effected by burning phosphorus in a confined volume of air, by the action of an alkaline solution of pyrogallol on air, by passing air over heated copper, or by the action of copper on air in the presence of ammoniacal solutions.
It does not burn, but supports the combustion of heated substances almost as well as oxygen.
It combines directly with lithium, calcium and magnesium when heated, whilst nitrides of the rare earth metals are also produced when their oxides are mixed with magnesium and heated in a current of nitrogen (C. Matignon, Comptes rendus, 1900, 131, p. 837).
When heated with the halogens, acetophenone is substituted in the aliphatic portion of the nucleus; thus bromine gives phenacyl bromide, C6H6CO.CH2Br.
In their natural condition the marekanite spheres are doubly refracting, but when they have been heated and very slowly cooled they lose this property and no longer exhibit any tendency to sudden disintegration.
The rise of conductivity with temperature, therefore, shows that the fluidity becomes greater when the solution is heated.
If a glucose solution be added to copper sulphate and much alkali added, a yellowish-red precipitate of cuprous hydrate separates, slowly in the cold, but immediately when the liquid is heated; this precipitate rapidly turns red owing to the formation of cuprous oxide.
The milk is then carefully dried by turning the mould round and round in the smoke produced by burning wood mixed with certain oily palm nuts; those of A ttalea excelsa are considered best, the smoke being confined within certain limits by the narrowness of the neck of the pot in which the nuts are heated.
In some districts the collected milk is heated alone or diluted with water, to coagulate the rubber, but if heated alone an inferior rubber is apt to result owing to overheating.
When solid caoutchouc is strongly heated it breaks down, without change in its ultimate composition, into a number of simpler liquid hydrocarbons of the terpene class (dipentene, di-isoprene, isoprene, &c.), of which one, isoprene (C5H8), is of simpler structure than oil of turpentine (C 10 H 16), from which it can also be obtained by the action of an intense heat.
When caoutchouc is heated slightly above the temperature of boiling water it becomes softer and loses much of its elasticity, which, however, it recoveres on cooling.
Air goods, such as cushions, beds, gas bags, and so forth, are made of textile fabrics which have been coated with mixed rubber either by the spreading process above described, or by means of heated rollers, the curing being then effected by steam heat.
Many of the residences and business places of Bowling Green are heated by a privately owned central hot-water heating plant.
As a preliminary to the melting process, the "browse" left in the preceding operation (half-fused and imperfectly reduced ore) is introduced with some peat and coal, and heated with the help of the blast.
When zinc is placed on the lead (heated to above the melting-point of zinc), liquefied and brought into intimate contact with the lead by stirring, gold, copper, silver and lead will combine with the zinc in the order given.
Pans and pot are heated from separate fire-places.
It ignites when heated in air with the formation of the monoxide; dilute acids convert it into metallic lead and lead monoxide, the latter dissolving in the acid.
These are knocked off, ground up with water, freed from metal-particles by elutriation, and the paste of white lead is allowed to set and dry in small conical forms. The German method differs from the Dutch inasmuch as the lead is suspended in a large chamber heated by ordinary means, and there exposed to the simultaneous action of vapour of aqueous acetic acid and of carbon dioxide.
When mixed with sodium carbonate and heated on charcoal in the reducing flame lead salts yield malleable globules of metal and a yellow oxide-ring.
In the Democratic national convention at Chicago in 1896, during a long and heated debate with regard to the party platform, Bryan, in advocating the "plank" declaring for the free coinage of silver, of which he was the author, delivered a celebrated speech containing the passage, "You shall not press down upon the brow of labour this crown of thorns; you shall not crucify mankind upon a cross of gold."
After a heated contest Mr Bryan again suffered a decisive defeat, President Taft securing 321 electoral votes to Mr Bryan's 162.
When heated with hydriodic acid and phosphorus it forms phenylacetic acid; whilst concentrated hydrobromic acid and hydrochloric acid at moderate temperatures convert it into phenylbromand phenylchlor-acetic acids.
When heated it loses water and forms pyraconitine.
The ring thus prepared was placed in a cast-iron box and heated in a gas furnace.
The magnetometric method was employed, and the metals, in the form of ovoids, were heated by a specially designed burner, fed with gas and air under pressure, which directed 90 fine jets of flame upon the asbestos covering the ovoid.
Now iron, nickel and cobalt all lose their magnetic quality when heated above certain critical temperatures which vary greatly for the three metals, and it was suspected by Faraday 3 as early as 1845 that manganese might really be a ferromagnetic metal having a critical temperature much below the ordinary temperature of the air.
He considers that Hall's is the fundamental phenomenon, and that the Nernst effect is essentially identical with it, the primary electromotive force in the case of the latter being that of the Thomson effect in the unequally heated metal, while in the Hall experiment it is derived from an external source.
Finding his relatives unsympathetic, and falling into heated controversy with the Presbyterian clergy, he made no long stay, but returned to Paris, where he remained for seven years, becoming professor in several colleges successively.
When heated with alcoholic potassium cyanide they are converted into benzoins.
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.
In the preparation of alum from clays or from bauxite, the material is gently calcined, then mixed with sulphuric acid and heated gradually to boiling; it is allowed to stand for some time, the clear solution drawn off and mixed with acid potassium sulphate and allowed to crystallize.
When cryolite is used for the preparation of alum, it is mixed with calcium carbonate and heated.
When heated to nearly a red heat it gives a porous friable mass which is known as "burnt alum."
It burns when heated in air, and is soluble in warm concentrated sulphuric acid.
It is a white amorphous infusible powder, which when strongly heated in sulphuretted hydrogen, yields an oxysulphide.
When heated in a current of carbon dioxide it forms the oxychloride CbOC1 3, and carbon monoxide.
Columbium pentachloride, CbC1 5, is obtained in yellow needles when a mixture of the pentoxide and sugar charcoal is heated in a current of air-free chlorine.
The oxyfluoride, CbOF 3, results when a mixture of the pentoxide and fluorspar is heated in a current of hydrochloric acid.
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.
It burns when heated in air, forming the pentoxide and sulphur dioxide.
Above these they are less regular and are attracted northward by the heated llanos of Venezuela in winter, or southward by the heated campos of Matto Grosso in summer.
In summer, becoming warmed by the heated surface of the plateau, they sweep across it without a cloud or drop of rain.
In winter the plateau is less heated, and cold currents of air from the west and south-west cause precipitation over a part if not all of this region.
It explodes when heated.
When strongly heated they decompose, forming fatty acids, nitrogen peroxide and nitrogen.
When heated with water and mineral acids, the nitrolic acids are completely decomposed, yielding fatty acids and nitrous oxide.
The experiment is easily made on a laboratory scale, with a small source of light, the rays from which, in their course towards a rather distant screen, are disturbed by the neighbourhood of a heated body.
Rosell, Ber., 1890, 23, p. 487), or from the aminoazo compound and a mustard oil, the resulting thiocarbanilido derivative being heated with acetic acid (M.
It fires when heated in air, and dissolves in acids to form uranous salts.
Ammonium uranate heated to redness yields pure U308, which serves as a raw material for uranium compounds.
In the English process the bars are heated cautiously on an inclined hearth, when relatively pure tin runs off, while a skeleton of impure metal remains.
The basin, made scrupulously clean, is heated to beyond the fusing point of tin.
The iron plates, having been carefully cleaned with sand and hydrochloric or sulphuric acid, and lastly with water, are plunged into heated tallow to drive away the water without oxidation of the metal.
Stannous oxalate when heated by itself in a tube leaves stannous oxide.
It is insoluble in water and in nitric acid and apparently so in hydrochloric acid; but if heated with this last for some time it passes into a compound, which, after the acid mother liquor has been decanted off, dissolves in water.
Tin compounds when heated on charcoal with sodium carbonate or potassium cyanide in the reducing blowpipe flame yield the metal and a scanty ring of white Sn02.
When slowly heated in a vacuum vessel until ignition takes place, some nitrogen dioxide, N02, is also produced.
When heated with zinc dust, it yields ethylene and water.
These laws are enforced by mine inspectors of the timber produces falls of ground, making necessary the excavawho are empowered to call upon the courts and other government tion and removal at times of hundreds of tons of heated rock and burning coal, in order to reach the fire.
In such cases the establishment of dressingrooms, properly heated, and connected with the mine by covered passages will be necessary.
Fischer, Ber., 1884, 17, p. 102); by passing the vapours of orthoaminodiphenylmethane over heated litharge (0.
Silver oxide, mixed as a paint and spread on the surface of a piece of glass and heated, gives a permanent yellow stain.
The desired result is obtained either by moving the manufactured goods gradually away from a constant source of heat, or by placing them in a heated kiln and allowing t he heat gradually to die out.
The empty crucible, having first been gradually dried and heated to a bright red heat in a subsidiary furnace, is taken up by means of massive iron tongs and introduced into the previously heated furnace, the temperature of which is then gradually raised.
For this purpose a cylinder of fireclay, provided with a square axial hole at the upper end, is heated in a small subsidiary furnace and is then introduced into the molten glass.
The crucible with the semi-solid glass which it contains is now allowed to cool considerably in the melting furnace, or it may be removed to another slightly heated furnace.
Lumps of glass of approximately the right weight are chosen, and are heated to a temperature just sufficient to soften the glass, when the lumps are caused to assume the shape of moulds made of iron or fireclay either by the natural flow of the softened glass under gravity, or by pressure from suitable tools or presses.
The Venetian furnaces in the island of Murano are small low structures heated with wood.
The manufactured goods are either removed gradually from a constant source of heat by means of a train of small iron trucks drawn along a tramway by an endless chain, or are placed in a heated kiln in which the fire is allowed gradually to die out.
In the viscous state a mass of glass can be coiled upon the heated end of an iron rod, and if the rod is hollow can be blown into a hollow bulb.
The fractured end is heated, and by the combined action of heat and centrifugal force opens out into a flat foot.
The fractured edge of the bowl is heated, trimmed with scissors and melted so as to be perfectly smooth and even, and the bowl itself receives its final form from the sugar-tongs tool.
The glass in process of fusion is contained in a basin or tank built up of large blocks of fire-clay and is heated by one or more powerful gas flames which enter the upper part of the furnace chamber through suitable apertures or " ports."
With producer gas it is necessary to pre-heat both the gas and the air which is supplied for its combustion by passing both through heated regenerators (for an account of the principles of the regenerative furnace see article Furnace).
Next, the rest of the connecting neck is detached from the cylinder by the application of a heated iron to the chilled glass.
The mould is in two, pieces hinged together; it is heated and the inner surface is rubbed over with finely powdered plumbago.
Before the glass is introduced, the annealing kiln is heated to dull red by means of coal fires in grates which are provided at the ends or sides of the kiln for that purpose.
Although the moulds are heated, the surface of the glass is always slightly ruffled by contact with the mould.
These small furnaces are usually heated by an oil spray under the pressure of steam or compressed air.
Having severed the body of the vase from the blowing iron, he heated and closed the fractured base, whilst holding the vase by means of the rod fixed in the neck.
It is probable that when the metal rod was withdrawn the vessel was filled with sand, to prevent collapse, and buried in heated ashes to anneal.
It is attacked rapidly by fluorine at ordinary temperature, and by chlorine when heated in a current of the gas.
It is decomposed with great violence when heated in contact with either sodium or potassium.
The solution on evaporation deposits a hydrated form, H 2 SiF 6.2H 2 O, which decomposes when heated.
Berzelius (Jahresb., 182 5, 4, p. 91) by the action of chlorine on silicon, and is also obtained when an intimate mixture of silica and carbon is heated in a stream of chlorine and the products of reaction fractionated.
When heated with the alkali and alkaline earth metals it yields silicon and the corresponding metallic chlorides.
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).
Silicon sulphide, SiS 2, is formed by the direct union of silicon with sulphur; by the action of sulphuretted hydrogen on crystallized silicon at red heat (P. Sabatier, Comptes rendus, 1880, 90, p. 819); or by passing the vapour of carbon bisulphide over a heated mixture of silica and carbon.
All carbonates, except those of the alkali metals and of thallium, are insoluble in water; and the majority decompose when heated strongly, carbon dioxide being liberated and a residue of an oxide of the metal left.
When heated with ammonia it yields guanidine, and on boiling with alcoholic potash it yields potassium carbonate.
When heated with ammonia it yields urethane.
As liquidity might be looked upon as the ne plus ultra of softness, this is the right place for stating that, while most metals, when heated up to their melting points, pass pretty abruptly from the solid to the liquid state, platinum and iron first assume, and throughout a long range of temperatures retain, a condition of viscous semi-solidity which enables two pieces of them to be "welded" together by pressure into one continuous mass.
All other metals, when heated in oxygen or air, are converted, more or less readily, into stable oxides.
Sulphur.-Amongst the better known metals, gold and aluminium are the only ones which, when heated with sulphur or in sulphur vapour remain unchanged.
Of the several products, the chlorides of gold and platinum (AuC13 and PtC1 4) are the only ones which when heated beyond their temperature of formation dissociate into metal and chlorine.
The ultimate chlorination product of copper, CuC1 2, when heated to redness, decomposes into the lower chloride, CuCI, and chlorine.
All the rest, when heated by themselves, volatilize, some at lower, others at higher temperatures.
When l-gulonic acid is heated with pyridine, it is converted into l-idonic acid, and vice versa; and d-gulonic acid may in a similar manner be converted into d-idonic acid, from which it is possible to prepare d-idose.
Lastly, when d-galactonic acid is heated with pyridine, it is converted into talonic acid, which is reducible to talose, an isomeride bearing to galactose the same relation that mannose bears to glucose.
In Barbadoes there are still many estates making good Mascabado sugar; but as the juice is extracted from the canes by windmills, and then concentrated in open kettles heated by direct fire, the financial results are disastrous, since nearly half the yield obtainable from the canes is lost.
In Cuba, Martinique, Peru and elsewhere the old-fashioned double-bottomed defecator is used, into which the juice is run direct, and there limed and heated.
The juice is then drawn off and pumped up to one of the double-bottomed defecators and redefecated, or, where juice-heaters have been used instead of defecators, the scums from the separators or subsiders are heated and forced through filter presses, the juice expressed going to the evaporators and the scum cakes formed in the filter presses to the fields as manure.
These pans are sometimes heated by boiling oil, with the idea that under such conditions the sugar which is kept stirred all the time as it thickens cannot be burnt or caramelized; but the same object can be attained more economically with steam of a given pressure by utilizing its latent heat.
When Cuba was the chief sugar-producing country making clayed sugars it was the custom (followed in refineries and found advantageous in general practice) to discharge the strike of crystallized sugar from the vacuum pan into a receiver heated below by steam, and to stir the mass for a certain time, and then distribute it into the moulds in which it was afterwards clayed.
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.
When the new cell comes into operation and becomes the head of the battery, the first or tail cell is thrown out, and number two becomes the tail cell, and so the rounds are repeated; one cell is always being emptied and one filled or charged with slices and heated up, the latter becoming the head of the battery as soon as it is ready.
The cistern being thus packed and settled is closed, and the syrup from the bag filters, heated up to nearly boiling point, is admitted at the top until the cistern is quite full.
A cistern well packed with 20 tons of char will hold, in addition, about io tons of syrup, and after settling, this can be pressed out by allowing second quality syrup, also heated to nearly boiling point, to enter the cistern slowly from the top, or it may be pressed out by boiling water.
Granulated sugar, so called, is made by passing the crystals, after leaving the centrifugals, through a large and slightly inclined revolving cylinder with a smaller one inside heated by steam.
The sugar fed into the upper end of the cylinder gradually works its way down to the lower, showering itself upon the heated central cylinder.
Pure carbonate of lime when heated loses 44% of its weight, the decrease being due to the loss of carbon dioxide gas.
Heated with many metals it converts them into oxides, and with combustible substances, such as charcoal, sulphur, &c., a most intense conflagration occurs.
The roasting is most simply effected by spreading it on heated slabs, on which it is constantly turned, or a roasting machine is used, consisting of a revolving drum in which the tobacco is rotated, gradually passing from one end to the other, and all the time under the influence of a current of heated air.
Some fortysix or more retorts, arranged in parallel horizontal rows, are heated in one furnace.
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.
If zinc be heated to near its boiling-point, it catches fire and burns with a brilliant light into its powdery white oxide, which forms a reek in the air (lana philosophica, " philosopher's wool").
The precipitate, when heated, passes into oxide, which is yellow in the heat and white after cooling; and, if it be moistened with cobalt nitrate solution and re-heated, it exhibits a green colour after cooling.
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.
Practically the first of these furnaces was that of Despretz, in which the mixture to be heated was placed in a carbon tube rendered incandescent by the passage of a current through its substance from end to end.
A thin carbon pencil, forming a bridge between two stout carbon rods, is set in the midst of the mixture to be heated.
On passing a current through the carbon the small rod is heated to incandescence, and imparts heat to the surrounding mass.
When heated in air it burns brilliantly with the formation of the oxide.
By passing chloroform vapour over the heated dioxide the tetradiand tri-chlorides are formed, together with the free metal and a gaseous hydride, TiH 4 (Renz, Ber., 1906, 39, p. 2 49).
Primary amines when heated with alcoholic potash and chloroform yield isonitriles, which are readily detected by their offensive smell.
Primary amines heated with carbon bisulphide in alcoholic solution are converted into mustard oils, when the dithiocarbamate first produced is heated with a solution of mercuric chloride.
When heated with alkyl or aryl iodides, they are converted into secondary and tertiary amines.
When heated with concentrated sulphuric acid for some time, they are sulphonated.
When heated with monobasic saturated acids and zinc chloride it yields acridines.
Sometimes, especially at early dawn, there is a musical noise in the desert, like the sound of distant drums, which is caused by the eddying of grains of sand in the heated atmosphere, on the crests of the medanos.
The substance is heated in a retort a, which consists of a large bulb drawn out at the top to form a long neck; it may also FIG.
Practically any vessel may serve as a receiver - test tube, flask, beaker, &c. If noxious vapours come over, it is necessary to have an air-tight connexion between the condenser and receiver, and to pro vide the latter with an outlet tube leading to an absorption column or other contrivance in which the vapours are taken up. If the substances operated upon decompose when heated in air, as, for example, the zinc alkyls which inflame, the air within the apparatus is replaced by some inert gas, e.g.
The theory of fractional distillation, or the behaviour of liquid mixtures when heated to their boiling-points, is more complex.
The most favourable retort is a shallow iron pan heated in a sand bath, and provided with a screwed-down lid bearing the delivery tube.
In its simplest form the apparatus consists of a straight tube, made of glass, porcelain or iron according to the temperature required and the nature of the reacting substances, heated in an ordinary combustion furnace, the mixture entering at one end and the vapours being condensed at the other.
Glass stills heated by a sand bath are sometimes employed in the final distillation of sulphuric acid; platinum, and an alloy of platinum and iridium with a lining of gold rolled on (a discovery due to Heraeus), are used for the same purpose.
The still is usually fed continuously by the heated water from the condenser.
It oxidizes rapidly when exposed to air, and burns when heated in air, oxygen, chlorine, bromine or sulphur vapour.
It dissociates when heated to a high temperature and is not affected by oxygen.
It is a white solid, which combines with gaseous ammonia to form SrC1 2.8NH 3, and when heated in superheated steam it decomposes with evolution of hydrochloric acid.
Strontium sulphide, SrS, is formed when the carbonate is heated to redness in a stream of sulphuretted hydrogen.
It loses carbon dioxide when heated to high temperature.
Taking magnesia alba, which he distinguished from limestone with which it had previously been confused, he showed that on being heated it lost weight owing to the escape of this fixed air (named carbonic acid by Lavoisier in 1781), and that the weight was regained when the calcined product was made to reabsorb the fixed air with which it had parted.
The metal is then heated, not to redness, but sufficiently to develop a certain degree of softness, and the workman, taking a very thin sheet of gold (or silver), hammers portions of it into the salient points of the design.
In this process cellulose (in the form of sawdust) is made into a stiff paste with a mixture of strong caustic potash and soda solution and heated in flat iron pans to 20o-250 C. The somewhat dark-coloured mass is lixiviated with a small amount of warm water in order to remove excess of alkali, the residual alkaline oxalates converted into insoluble calcium oxalate by boiling with milk of lime, the lime salt separated, and decomposed by means of sulphuric acid.
When heated with glycerin to ioo C. it yields formic acid and carbon dioxide; above this temperature, allyl alcohol is formed.
When heated with phosphorus pentoxide it yields cyanogen.
A nickel steel containing 36% of nickel has the property of retaining an almost constant volume when heated or cooled through a considerable range of temperature; it is therefore useful for the construction of pendulums and for measures of length.
To find the total heat of a substance in any given state defined by the values of p and 0, starting from any convenient zero of temperature, it is sufficient to measure the total heat required to raise the substance to the final temperature under a constant pressure equal to p. For instance, in the boiler of a steam engine the feed water is pumped into the boiler against the final pressure of the steam, and is heated under this constant pressure up to the temperature of the steam.
Macquer and Lavoisier showed that when gold is strongly heated, fumes arise which gild a piece of silver held in them.
It is insoluble in hydrochloric, nitric and sulphuric acids, but dissolves in aqua regia - a mixture of hydrochloric and nitric acids - and when very finely divided in a heated mixture of strong sulphuric acid and a little nitric acid; dilution with water, however, precipitates the metal as a violet or brown powder from this solution.
Varrentrapp pointed out that " cornets " from the assay of gold may retain gas if they are not strongly heated.
It has been found that the reaction proceeds faster when the solution is heated.
After well washing with water, the slimes are roughly dried in bag-filters or filter-presses, and then treated with dilute sulphuric acid, the solution being heated by steam.
It shows the influence of Arminian theology against Calvinism, which was vigorously upheld in the Quin-particular formula, put forward by the synod of Dort in 1619 to uphold the five points of Calvinism, after heated discussion, in which English delegates took part, of the problems of divine omniscience and human free-will.
In the liquation process the ore is heated in inclined cylindrical retorts, and the molten metal is tapped at the lower end; the residues being removed from the upper end.
The metal oxidizes very slowly in dry air at ordinary temperatures, but somewhat more rapidly in moist air or when heated.
When heated to 200 0 it assumes the crystalline form of bismuthite.
On this ground Maxwell inferred that the forces acting in the radiometer are connected with gliding of the gas along the unequally heated boundaries; and as the laws of this slipping, as well as the constitution of the adjacent layer, are uncertain, the problem becomes very intricate.
In general these compounds are decomposable by heat, but some of them, such as those of gold, silver, copper and the alkali metals, even when heated above the boiling point of mercury retain mercury and leave residues of definite composition.
For higher temperatures the bulb of the vapour density tube is made of porcelain or platinum, and is heated in a gas furnace.
When heated in a current of hydrogen it sublimes in the form of brilliant prismatic crystals.
When heated in air, tellurium burns, forming the dioxide Te02.
The trioxide is an orangecoloured solid which is formed when telluric acid is strongly heated.
When heated in air the metal burns if in the form of thin wire, and is superficially oxidized if more compact.
It is unaffected by any acid or mixture of acids, but burns to the pentoxide when heated.
It forms colourless, very hygroscopic prisms, which attack glass, slowly at ordinary temperatures, more rapidly when heated (Ber., 1909, 4 2, p. 49 2).
There is no difficulty in observing the temperature of the surface of the sea on board ship, the only precautions required being to draw the water in a bucket which has not been heated in the sun in summer or exposed to frost in winter, to draw it well forward of any discharge pipes of the steamer, to place it in the shade on deck, insert the thermometer immediately and make the reading without delay.
The most important class of coals is that generally known as bituminous, from their property of softening or undergoing an apparent fusion when heated to a temperature far below that at which actual combustion takes place.
When coal is heated to redness out of contact with the air, the more volatile constituents, water, hydrogen, oxygen, and nitrogen are in great part expelled, a portion of the carbon being also volatilized in the form of hydro carbons and carbonic oxide,-the greater part, however, remaining behind, together with all the mineral matter or ash, in the form of coke, or, as it is also called, " fixed carbon."
The former class undergo an incipient fusion or softening when heated, so that the fragments coalesce and yield a compact coke, while the latter (also called free-burning) preserve their form, producing a coke which is only serviceable when made from large pieces of coal, the smaller pieces being incoherent and of no value.
They found that if liquid acetylene in a steel bottle be heated at one point by a platinum wire raised to a red heat, the whole mass decomposes and gives rise to such tremendous pressures that no cylinder would be able to withstand them.
The essence of this process is that the coke and lime are only heated to the point of combination, and are not 3 to 82 5 to 72 13 to 75 4 to 22 5 to 13 colours.
The carbide is heated to complete liquefaction and tapped at short intervals.
In 1818 he saved Paris from a financial crisis by buying a large amount of stock, but next year, in consequence of his heated defence of the liberty of the press and the electoral law of 1867, the governorship of the Bank was taken from him.
The term is more customarily given to productions of flame such as we have in the burning of oils, gas, fuel, &c., but it is conveniently extended to other cases of oxidation, such as are met with when metals are heated for a long time in air or oxygen.
In the year before (1742) he had planned the " Pennsylvania fire-place," better known as the " Franklin stove," which saved fuel, heated all the room, and had the same principle as the hot-air furnace; the stove was never patented by Franklin, but was described in his pamphlet dated 1744.
By one of those waves of popular feeling to which the Japanese people are peculiarly liable, the nation which had supported him up to a certain point suddenly veered round and opposed him with heated violence.
This anhydrous chloride is reduced to a lower chloride, of composition SmC1 2, when heated to a high temperature in a current of hydrogen or ammonia (Matignon and Cazes, Coupes rendus, 2906, 142, p. 183).
The carbide, SmC2, is formed when the oxide is heated with carbon in the electric furnace.
Dioxyand tetraoxy-anthraquinones are obtained when meta-oxyand dimeta-dioxy-benzoic acids are heated with concentrated sulphuric acid.
As an alternative the osmiridium is fused with zinc, the regulus treated with hydrochloric acid, and then heated with barium nitrate and barium peroxide.
The protoxide, OsO, is obtained as a dark grey insoluble powder when osmium sulphite is heated with sodium carbonate in a current of carbon dioxide.
The dioxide, 0s0 2, is formed when potassium osmichloride is heated with sodium carbonate in a current of carbon dioxide, or by electrolysis of a solution of the tetroxide in the presence of alkali.
The tetroxide, 0s04, is formed when osmium compounds are heated in air, or with aqua regia, or fused with caustic alkali and nitre.
Osmium dichloride, OsC1 21 is obtained as a dark coloured powder when the metal is heated in a current of chlorine.
Potassium osmichloride, K 2 OsC1 6, is formed when a mixture of osmium and potassium chloride is heated in a current of chlorine, or on adding potassium chloride and alcohol to a solution of the tetroxide in hydrochloric acid.
The powdery metal burns readily in air; the crystalline metal requires to be heated in an oxyhydrogen flame before it catches fire.
For its extraction from zircon the mineral is heated and quenched in water to render it brittle, and then reduced to a fine powder, which is fused with three to four parts of acid potassium fluoride in a platinum crucible.
When the mass is quietly fusing, the crucible is heated for two hours in a wind-furnace.
Zirconia, when heated to whiteness, remains unfused, and radiates a fine white light, which suggested its utilization for making incandescent gas mantles; and, in the form of disks, as a substitute for the lime-cylinders ordinarily employed in "limelight."
Zirconium hydride, ZrH2, is supposed to be formed when zirconia is heated with magnesium in an atmosphere of hydrogen.
Zirconium iodide, Zr14, was obtained as a yellow, microcrystalline solid by acting with hydriodic acid on heated zirconium (Wedekind, Ber., 1904, 37, p. 1135).
Good graphite crucibles can be used many times in succession if they are heated gradually each time, but they are usually discarded after about fifteen or twenty meltings.
They are heated in circular furnaces 21 in.
The blanks fall through an aperture after having been heated for a few minutes.
When boiled with water it forms the ortho-acid, and when heated to redness the metaacid.
The name seems to have been given originally to the Spanish phosphorite, probably because it phosphoresced when heated.
When the wire was heated by an electric current a fine line of vapour descended from each drop. The pipe was closed at the centre by a membrane which prevented a through draught, yet permitted the vibrations, as it was at a node.
When heated with hydrochloric acid it gives isopilocarpine.
Calcium phosphide, Ca 3 P 2, is obtained as a reddish substance by passing phosphorus vapour over strongly heated lime.
It is particularly noteworthy from the phosphorescence which it exhibits when heated, or after exposure to the sun's rays; hence its synonym "Canton's phosphorus," after John Canton (1718-1772), an English natural philosopher.
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.
The hydrogen in ammonia is capable of replacement by metals, thus magnesium burns in the gas with the formation of magnesium nitride Mg3N2, and when the gas is passed over heated sodium or potassium, sodamide, NaNH 2, and potassamide, KNH 2, are formed.
It decomposes silicates on being heated with them.
After some heated discussion a compromise was arrived at.
The apparatus described in the patent specification is an iron cylinder heated by gas rings below, with a narrower cylinder beneath, through which passes upwards a stout iron cathode rod cemented in place by caustic soda solidified in the narrower vessel.
Heated in a current of carbon dioxide sodamide yields caustic soda and cyanamide, and with nitrous oxide it gives sodium azoimide; it deflagrates with lead or silver nitrate and explodes with potassium chlorate.
It burns when heated in dry air, and ignites in moist air; it is decomposed by water, giving caustic soda and hydrogen.
In practice the metal is placed on aluminium trays traversing an iron tube heated to 300 0, through which a current of air, freed from moisture and carbon dioxide, is passed; the process is made continuous, and the product contains about 93% Na202.
Sodium dioxide is chiefly employed as an oxidizing agent, being used in mineral analysis and in various organic preparations; it readily burns paper, wood, &c., but does not evolve oxygen unless heated to a high temperature.
Charcoal burns when heated in air, usually without the formation of flame, although a flame is apparent if the temperature be raised.
It burns when heated in an atmosphere of oxygen, forming carbon dioxide, and when heated in sulphur vapour it forms carbon bisulphide.
When heated with nitrogenous substances, in the presence of carbonated or caustic alkali, it forms cyanides.
It does not burn, and does not support ordinary combustion, but the alkali metals and magnesium, if strongly heated, will continue to burn in the gas with formation of oxides and liberation of carbon.
When heated in air it fuses and then takes fire, burning into a mixture of oxides.
When the oxide-free metal is heated gently in dry ammonia it is gradually transformed into a blue liquid, which on cooling freezes into a yellowish-brown or flesh-coloured solid, potassamide, KNH 2.
When heated to redness the amide is decomposed into ammonia and potassium nitride, NK 3, which is an almost black solid.
A solution of one part of the carbonate in 12 parts of water is heated to boiling in a cast-iron vessel (industrially by means of steampipes) and the milk of lime added in instalments until a sample of the filtered mixture no longer effervesces with an excess of acid.
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.
The blister if unbroken was heated, pricked, and then rubbed level with a burnisher; if, as sometimes happened, the silver had flaked away it was replaced by coatings of pure leaf silver rubbed in with a burnisher.
In making the acid by this process benzaldehyde, acetic anhydride and anhydrous sodium acetate are heated for some hours to about 180 C., the resulting product is made alkaline with sodium carbonate, and any excess of benzaldehyde removed by a current of steam.
Brown rods may also be buffed by sinking them in cold water which is heated to boiling point, and maintained at that temperature for the requisite period.
If a long glass tube with plane ends, and containing some pellets of sodium is heated in the middle by a row of burners, the cool ends remain practically vacuous and do not become obscured.
The sodium vapour in the middle is very dense on the heated side, the density diminishing rapidly towards the upper part of the tube, so that, although not prismatic in form, it refracts like a prism owing to the variation in density.
If the sodium is only gently heated, so as to produce a comparatively rarefied vapour, and a grating spectroscope employed, the spectrum obtained is like that shown in fig.
Hydriodic acid, HI, is formed by the direct union of its components in the presence of a catalytic agent; for this purpose platinum black is used, and the hydrogen and iodine vapour are passed over the heated substance.
Nitrous acid and chlorine readily decompose them with liberation of iodine; the same effect being produced when they are heated with concentrated sulphuric acid and manganese dioxide.
As the frame has the same linear expansion as the wire, external changes of the temperature will not affect their relative length, but if the fine wire is heated by the passage of an electric current, its expansion will move the indicating needle over the scale, the motion being multiplied by the gear.
When heated in contact with air they undergo a certain amount of oxidation, being converted to some extent into the corresponding cyanate.
When heated it yields mercury, cyanogen and paracyanogen.
This is heated to boiling, and the residue after filtration contains about 30% of Prussian blue.
The free acid, when heated with concentrated sulphuric acid, is decomposed into water and pure carbon monoxide; when heated with nitric acid, it is oxidized first to oxalic acid and finally to carbon dioxide.
The calcium salt, when heated with the calcium salts of higher homologues, gives aldehydes.
The silver and mercury salts, when heated, yield the metal, with liberation of carbon dioxide and formation of free formic acid; and the ammonium salt, when distilled, gives some formamide, Hconh 2.
Charcoal is valuable for its infusibility and low conductivity for heat (allowing substances to be strongly heated upon it), and for its powerful reducing properties; so that it is chiefly employed in testing the fusibility of minerals and in reduction.
Fletcher, in which the blast is heated by passing through a copper coil heated by a separate burner, is only of service when a pointed flame of a fairly high temperature is required.
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.
Chromium and its salts may be detected by the fact that they give a deep green bead when heated with borax, or that on fusion with sodium carbonate and nitre, a yellow mass of an alkaline chromate is obtained, which, on solution in water and acidification with acetic acid, gives a bright yellow precipitate on the addition of soluble lead salts.
Heated with concentrated hydrochloric acid it liberates chlorine, and with sulphuric acid it liberates oxygen.
The fluoride, CrF3, results on passing hydrofluoric acid over the heated chloride, and sublimes in needles.
Potassium chlorochromate, CrO 2 Cl OK, is produced when potassium bichromate is heated with concentrated hydrochloric acid and a little water, or from chromium oxychloride and saturated potassium chloride solution, when - it separates as a red crystalline salt.
When heated with aniline and aniline hydrochloride they yield indulines.
The reel to which the raw silk is led consists of a light six-armed frame, enclosed within a wooden casing having a glass frame in front, the enclosure being heated with steam-pipes.
The silk is then partly dried in a hydro-extractor, and afterwards put in rooms heated by steam-pipes, where the drying is completed.
Gases, like atmospheric air, hydrogen or carbon dioxide do not become luminous if they are placed in tubes, even when heated up far beyond white heat as in the electric furnace.
It is only recently that owing to the introduction of carbon tubes heated electrically the excitement of the luminous vibrations of molecules by temperature alone has become an effective method for the study of their spectra even in the case of metals.
This is consistent with Kirchhoff's law and shows that the sodium in a flame possesses the same relative radiation and absorption as sodium vapour heated thermally to the temperature of the flames.
The fact that the gases with which we are most familiar are not rendered luminous by being heated in a tube to a temperature well above a white heat has often been a stumbling block and raised the not unreasonable doubt whether approximately homogeneous oscillations could ever be obtained by a mere thermal process.
In combustion the particulae nitro-aereae - either pre-existent in the thing consumed or supplied by the air - combined with the material burnt; as he inferred from his observation that antimony, strongly heated with a burning glass, undergoes an increase of weight which can be attributed to nothing else but these particles.
Heated with anhydrous sodium acetate and acetic anhydride it gives cinnamic acid; with ethyl bromide and sodium it forms triphenyl-carbinol (C 6 H 5) 3 C OH; with dimethylaniline and anhydrous zinc chloride it forms leuco-malachite green C6H5CH[C6H4N(CH3)2]2; and with dimethylaniline and concentrated hydrochloric acid it gives dimethylaminobenzhydrol, C 6 H 5 CH(OH)C 6 H 4 N(CH 3) 2.
Graetzel's process, which was at one time employed, consisted in electrolysing the chloride in a metal crucible heated externally, the crucible itself forming the cathode, and the magnesium being deposited upon its inner surface.
Borchers also used an externally heated metal vessel as the cathode; it is provided with a supporting collar or flange a little below the top, so that the upper part of the vessel is exposed to the cooling influence of the air, in order that a crust of solidified salt may there be formed, and so prevent the creeping of the electrolyte over the top. The carbon anode passes through the cover of a porcelain cylinder, open at the bottom, and provided with a side-tube at the top to remove the chlorine formed during electrolysis.
Smaller pieces are thrown into a bath of melted carnallite and pressed together with an iron rod, the bath being then heated until the globules of metal float to the top, when they may be removed in perforated iron ladles, through the holes in which the fused chloride can drain away, but through which the melted magnesium cannot pass by reason of its high surface tension.
It also burns when heated in a current of steam, which it decomposes with the liberation of hydrogen and the formation of magnesia.
When magnesium is heated in fluorine or chlorine or in the vapour of bromine or iodine there is a violent reaction, and the corresponding halide compounds are formed.
The solution is evaporated, and the residue strongly heated, when water and ammonium chloride are expelled, and anhydrous magnesium chloride remains.
Magnesium oxychloride when heated to redness in a current of air evolves a mixture of hydrochloric acid and chlorine and leaves a residue of magnesia, a reaction which is employed in the Weldon-Pechiney and Mond processes for the manufacture of chlorine.
When heated in dry oxygen it becomes incandescent, forming magnesia.
When heated in a current of carbon monoxide or dioxide, it is converted into oxide, some carbon and cyanogen being formed at the same time.
Water is led into the highest basin and by the action of the heated gases is soon brought into a state of ebullition; after remaining in this basin for about a day, it is run off into the second one and is treated there in a similar manner.
It is then run into settling tanks, from which it next passes into the evaporating pans, which are shallow leadlined pans heated by the gases of the soffioni.
The residue is then heated in a current of superheated steam, in which the boric acid volatilizes and distils over.
It follows that if the thermodynamic heat of solution be positive, that is, if heat be absorbed to keep the system at constant temperature, the solubility will increase with rising temperature, while if heat be evolved on dissolution, the solubility falls when the system is heated.
The metal in the form of thin turnings is charged into hard glass or iron tubes heated to a full red in a combustion furnace.
They are all decomposed when heated to a sufficiently high temperature, with evolution for the most part of oxygen and nitrogen peroxide, leaving a residue of oxide of the metal.
The resistance of lichens is extraordinary; they may be cooled to very low temperatures and heated to high temperatures without being killed.
In order to prepare pure alumina, bauxite and sodium carbonate were heated in a furnace until the reaction was complete; the product was then extracted with water to dissolve the sodium aluminate, the solution treated with carbon dioxide, and the precipitate removed and dried.
The whole was thrown in several portions on to the hearth of a furnace previously heated to low redness and was stirred at intervals for three hours.
The bath is heated internally with the current rather than by means of external fuel, because this arrangement permits the vessel itself to be kept comparatively cool; if it were fired from without, it would be hotter than the electrolyte, and no material suitable for the construction of the cell is competent to withstand the attack of nascent aluminium at high temperatures.
Aluminium chloride, AlC1 3, was first prepared by Oersted, who heated a mixture of carbon and alumina in a current of chlorine, a method subsequently improved by Wohler, Bunsen, Deville and others.
Aluminium sulphide, Al2S3, results from the direct union of the metal with sulphur, or when carbon disulphide vapour is passed over strongly heated alumina.
Aluminium sulphate, known commercially as "concentrated alum" or "sulphate of alumina," is manufactured from kaolin or china clay, whi