Manual of Practical Assaying: Intended for the Use of Metallurgists, Captains of Mines, and Assayers in General ...H. Bailliere, 1854 - 426 страници |
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added alkaline alloy ammonia angles antimony apparatus aqua regia arsenic ascertained assay bismuth black flux blow-pipe borax button Carats carbonate of soda carbonic acid charcoal chloride cobalt colour combustion containing cooling copper crucible crystalline crystals cube cupel decomposed dissolved edges employed excess filter flask furnace fused fusible fusion galena gangue gives glass globules gold grains grammes heat hydrochloric acid hydrogen lime liquid litharge manganese matrass matter mercury metallic microcosmic salt mineral mixed mixture molecules nickel nitrate nitric acid normal solution obtained octahedron operation Ounce oxide oxide of copper oxide of iron oxide of lead oxide of tin oxidising oxygen peroxide pipette placed Plates platinum potash powder precipitate prism produced proportion protoxide pure readily reducing flame rhombohedron roasting scorifier silica silver slag small quantity soluble standard substance sulphate sulphuret of antimony sulphuric acid temperature thousandths tion truncated tube vapour volatile vols washed weight yellow zinc
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Страница 48 - ... order substituting those who are not joined with him as defendants in his place. In either case the application is made in the same manner and is subject to the same provisions as if made as prescribed in section fourteen hundred and twenty-one of this act.
Страница 203 - Fahr., and then note its weight; it will be found to have lost a certain amount, which will correspond to the weight of the bulk of water it has displaced. Divide its weight in air by the loss of weight in water, and the quotient will be the required specific gravity. This will be more readily understood by an example. Suppose we find the mineral to weigh 80 grains in the air, and only 66 in water ; the loss ==80 — 66 = 14.
Страница 117 - ... and again cooled, and it will be found that the nonius has been moved forward a certain number of degrees or minutes. The scale of this pyrometer is readily connected with that of the thermometer by immersing the register in boiling mercury, whose temperature is as constant as that of boiling water, and has been accurately determined by the thermometer. The amount of expansion for a known number of degrees is thus determined, and the value of all other expansions may be considered as proportionate.
Страница 61 - ... sufficient to allow of its being grasped firmly in the hand, and below to permit a considerable grinding surface to come in contact with the mortar. Its diameter in the lower part may be about one-third or onefourth of the upper diameter of the mortar. The curve at the bottom should be of shorter radius than the curve of the mortar, that it may not touch the mortar in more than one part, whilst at the same time the interval around may gradually increase, though not too rapidly, towards the upper...
Страница 330 - ... of water, and a gentle heat applied. The sulphate of iron is gradually added in small quantities to the acid, so as to absorb the chlorine as it is evolved, and the addition of that salt continued till the liquid, after being heated, gives a blue precipitate with the red prussiate of potash, and has no smell of chlorine, which are indications that the protosulphate of iron is present in excess. By weighing what remains of the sulphate of iron, the quantity added is ascertained ; say m grains....
Страница 105 - ... adding the latter to effect the mixture, at first by stirring up the mass lightly with a pointed stick or fork ; it will then be found easy, by a little management, to obtain a good mixture without making it very moist. The luting ought to be made as dry as possible, consistent with facility in working it. The wetter it is, the more liable to crack in drying, and vice versa.
Страница 116 - ... forward from its first position; and this, though in any case but small, may be effected with great precision by means of the scale. This is independent of the register, and consists of two rules of brass, accurately joined together at a right angle by their edges, and fitting square upon two sides of the blacklead bar. At one end of this double rule a small plate of brass projects at a right angle, which may be brought down upon the shoulder of the register, formed by the notch cut away for...
Страница 105 - Iron cement. This mixture is used for making permanent joints generally between surfaces of iron. Clean iron borings, or turnings, are to be slightly pounded, so as to be broken but not pulverized ; the result is to be sifted coarsely, mixed with powdered sal ammoniac and sulphur, and enough water to moisten the whole slightly. It is then to be rammed or caulked into the joints, and the latter drawn together as tightly as possible.
Страница 203 - Scratches glass, though rather with difficulty, leaving its powder on it. Yields readily to the knife. 6. Scratches glass easily. Yields with difficulty to the knife. 7. Does not yield to the knife. Yields to the edge of a file, though with difficulty. 8. 9. 10. Harder than flint.
Страница 489 - In a second experiment, with the same anthracite and the same litharge, I obtained 450 grains of lead ; and in a third, only 350 grains. It is, therefore, obvious that this method of Berthier's is altogether nugatory for ascertaining the quantity of carbon in coals, and is worse than useless in judging of the calorific qualities of different kinds of fuel.