In the manufacture of tobacco for smoking, we have to do with the numerous forms of tobacco used for smoking in pipes, embracing cut smoking mixtures, cake or plug, and roll or spun tobacco.
All these mixtures when solidified may fairly be termed alloys.'
7 represents the specific volumes of mixtures of ammonium and potassium sulphates; the ordinates re presenting specific volumes, and the abscissae the per centage composition of the mixture.
Equal importance attached to faulty mixtures or dyscrasiae of the blood.
Semi-opacity and opacity are usually produced by the addition to the glass-mixtures of materials which will remain in suspension in the glass, such as oxide of tin, oxide of arsenic, phosphate of lime, cryolite or a mixture of felspar and fluorspar.
For this reason chemical agents are added to glass mixtures to remove or neutralize accidental colour.
The above theory, coupled with such facts as the variation of the composition of the constant boiling-point fraction with the pressure under which the mixture is distilled, the proportionality of the density of all mixtures to their composition, &c., shows this to be erroneous.
Dry distillation is extremely wasteful even when definite substances or mixtures, such as calcium acetate which yields acetone, are dealt with, valueless by-products being obtained and the condensate usually requiring much purification.
Dephlegmation of the vapours arising from such mixtures as coaltar fractions, petroleum and the "wash" of the spirit industry, is very important, and many types of apparatus are employed in order to effect a separation of the vapours.
It may conveniently be extended to similar mixtures of sulphur and selenium or tellurium, of bismuth and sulphur, of copper and cuprous oxide, and of iron and carbon, in fact to all cases in which substances can be made to mix in varying proportions without very marked indication of chemical action.
In the case of a pure substance, and of a certain small class of mixtures, there is no further fall in temperature until the substance has become completely solid, but, in the case of most mixtures, after the freezing-point has been reached the temperature soon begins to fall again, and as the amount of solid increases the temperature becomes lower and lower.
If we determine the freezing-points of a number of mixtures varying in composition from pure A to pure B, we can plot the freezing-point curve.
In one case, indeed, the average produce by mixed minerals and nitrogenous manure was more than that by the annual application of farmyard manure; and in seven out of the ten cases in which such mixtures were used the average yield per acre was from over two to over eight bushels more than the average yield of the United Kingdom (assuming this to be about twenty-eight bushels of 60 lb per bushel) under ordinary rotation.
The water in a soap is rarely directly determined; when it is, the soap, in the form of shavings, is heated to 105° C. until the weight is constant, the loss giving the amount of ' " Soap powders " and " soap extracts " are powdered mixtures of soaps, soda ash or ordinary sodium carbonate.
He emphasized that the practical training should include (1) the qualitative and quantitative analysis of mixtures, (2) the preparation of substances according to established methods, (3) original research - a course which has been generally adopted.
This law states that: - gases combine with one another in simple proportions by volume, and the volume of the product (if gaseous) has a simple ratio to the volumes of the original mixtures; in other words, the densities of gases are simply related to their combining weights.
A sublimate may be formed of: sulphur - reddish-brown drops, cooling to a yellow to brown solid, from sulphides or mixtures; iodine - violet vapour, black sublimate, from iodides, iodic acid, or mixtures; mercury and its compounds - metallic mercury forms minute globules, mercuric sulphide is black and becomes red on rubbing, mercuric chloride fuses before subliming, mercurous chloride does not fuse, mercuric iodide gives a yellow sublimate; arsenic and its compounds - metallic arsenic gives a grey mirror, arsenious oxide forms white shining crystals, arsenic sulphides give reddish-yellow sublimates which turn yellow on cooling; antimony oxide fuses and gives a yellow acicular sublimate; lead chloride forms a white sublimate after long and intense heating.
This subject is treated in the article Solution; for the properties of liquid mixtures reference should also be made to the article Distillation.
It converts many metallic oxides into mixtures of nitrates and nitrites, and attacks many metals, forming nitrates and being itself reduced to nitric oxide.
They pass through a viscous stage in cooling from a state of fluidity; they develop effects of colour when the glass mixtures are fused with certain metallic oxides; they are, when cold, bad conductors both of electricity and heat, they are easily fractured by a blow or shock and show a conchoidal fracture; they are but slightly affected by ordinary solvents, but are readily attacked by hydrofluoric acid.
Long experience has fixed the mixtures, so far as ordinary furnace temperatures are concerned, which produce the varieties of glass in common use.
The essential materials of which these mixtures are made are, for English flint glass, sand, carbonate of potash and red lead; for plate and sheet glass, sand, carbonate or sulphate of soda.
It is convenient to treat these glasses as " normal " glasses, but they are in reality mixtures of silicates, and cannot rightly be regarded as definite chemical compounds or represented by definite chemical formulae.
Is thick fleshy leaf of a dark colour, but scraps and waste pieces resulting from the preparation of smoking mixtures and cigars, and the midribs of leaves are largely used.
In practice, however, we never have to deal with pure zinc minerals, but with complex mixtures, which must first of all be subjected to mechanical operations, to remove at least part of the gangue, and if possible also of the heavy metallic impurities.
As ores of zinc are usually shipped before smelting from widely separated places - Sweden, Spain, Algiers, Italy, Greece, Australia and the Rocky Mountains region of North America - it is important that they be separated from their mixtures at the mines.
Numerous sulphonic acids of anthracene are known, a monosulphonic acid being obtained with dilute sulphuric acid, whilst concentrated sulphuric acid produces mixtures of the anthracene disulphonic acids.
The population of Peru is mixed, including whites, Indians, Africans, Asiatics, and their mixtures and sub-mixtures.
Other race mixtures consist of the zambos (the African-Indian cross), an Asiatic graft upon these various crosses, and an extremely confusing intermixture of the various crosses, for which the Spanish races have descriptive appellations.
The theory of fractional distillation, or the behaviour of liquid mixtures when heated to their boiling-points, is more complex.
For simplicity we confine ourselves to mixtures of two components, in which experience shows that three cases are to be recognized according as the components are (I) completely immiscible, (2) partially miscible, (3) miscible in all proportions.
The distillation of completely miscible mixtures is the most common practically and the most complex theoretically.
At one time it was thought that these mixtures of constant boiling-point (an extended list is given in Young's Fractional Distillation) were definite compounds.
On distilling such a mixture pure A will come over first, followed by mixtures in which the quantity of B continually increases; consequently by a sufficient number of distillations A and B can be completely separated.
Alligare, to combine), a term generally applied to the intimate mixtures obtained by melting together two or more metals, and allowing the mass to solidify.
All the mixtures whose composition lies between that of A and C deposit crystals of pure.
A when they begin to solidify, while mixtures between C and B in composition deposit crystals of pure B.
Experiments upon the growth of barley for fifty years in succession on rather heavy ordinary arable soil resulted in showing that the produce by mineral manures alone is larger than that without manure; that nitrogenous manures alone give more produce than mineral manures alone; and that mixtures of mineral and nitrogenous manure give much more than either used alone - generally twice, or more than twice, as much as mineral manures alone.
The conversion of nitrogen into ammonia by electricity has received much attention, but the commercial aspect appears to have been first worked out by de Hemptinne in 1900, who used both the spark and silent discharge on mixtures of hydrogen and nitrogen, and found that the pressure and temperature must be kept low and the spark gap narrow.
But many hold that his letters and essays are finer contributions to pure literature, and that on these exquisite mixtures of wisdom, pathos, melody and humour his fame is likely to be ultimately based.
Tschermak, in 1878, regarded them as isomorphous mixtures of the following fundamental molecules: H 2 KA1 3 (SiO 4) 3, corresponding with muscovite; Mg 6 Si 3 0 12, a hypothetical polymer of olivine; and H4S15012, a hypothetical silicic acid.
The use of the first two is restricted, as they are suited only for galena ores or mixtures of galena and carbonate, which contain not less than 58% lead and not more than 4% silica; further, ores to be treated in the ore-hearth should run low in or be free from silver, as the loss in the fumes is excessive.
Venetian white, Hamburg white and Dutch white are mixtures of one part of white lead with one, two and three parts of barium sulphate respectively.
Bradford was at one time the centre of the clothing industry in the west of England, and was especially famous for its broadcloths and mixtures, the waters of the Avon being especially favourable to the production of good colours and superior dyes.
In all such magnetizable alloys the presence of manganese appears to be essential, and there can be little doubt that the magnetic quality of the mixtures is derived solely from this component.
The alum schists employed in the manufacture of alum are mixtures of iron pyrites, aluminium silicate and various bituminous substances, and are found in upper Bavaria, Bohemia, Belgium and Scotland.
However this may be, it would always be possible, with the aid of a grating of given resolving power, to construct artificially from white light mixtures of slightly different wave-length whose resolution or otherwise would discriminate between powers inferior and superior to the given one.3 2 Compare also F.
The application of physiology to the explanation of diseases, and thus to practice, was chiefly by the theory of the temperaments or mixtures which Galen founded upon the Hippocratic doctrine of humours, but developed with marvellous and fatal ingenuity.
In coal-mines we have to deal with " fire-damp " or marsh gas, and with inflammable coal dust, which form explosive mixtures with air and frequently lead to disastrous explosions resulting in great loss of life.
Explosive mixtures of marsh-gas and air may be fired by an unprotected light.
Little is known about the actual cause of colour in glass beyond the fact that certain materials added to and melted with certain glass-mixtures will in favourable circumstances produce effects of colour.
The same oxide may produce different colours with different glass-mixtures, and different oxides of the same metal may produce different colours.
Glass mixtures containing lead are melted in covered, beehive-shaped crucibles holding from 12 to 18 cwt.
A certain proportion of soda ash (carbonate of soda) is also used in some works in sheet-glass mixtures, while " decolorizers " (substances intended to remove or reduce the colour of the glass) are also sometimes added, those most generally used being manganese dioxide and arsenic. Another essential ingredient of all glass mixtures containing sulphate of soda is some form of carbon, which is added either as coke, charcoal or anthracite coal; the carbon so introduced aids the reducing substances contained in the atmosphere of the furnace in bringing about the reduction of the sulphate of soda to a condition in which it combines more readily with the silicic acid of the sand.
9 illustrates the first case: the ordinates represent specific volumes, and the abscissae denote the composition of isomorphous mixtures of ammonium and potassium dihydrogen phosphates, which mutually take one another up to the extent of 20% to form homogeneous crystals.
Of mineral constituents, whether used alone or in mixture with nitrogenous manures, phosphates are much more effective than mixtures of salts of potash, soda and magnesia.
These discoveries of Geoffroy and Scheele formed the basis of Chevreul's researches by which he established the constitution of oils and the true nature of soap. In the article Oils it is pointed out that all fatty oils and fats are mixtures of glycerides, that is, of bodies related to the alcohol glycerin C 3H5(OH)3 i and some fatty acid such as palmitic acid (C 16 H 31 0 2)H.