Handbook of Chemistry, for School and Home Use

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Seite 73 - This is strikingly shown in an alloy called the " fusible metal," which is composed of 8 parts of bismuth, 5 of lead, and 3 of tin, and melts at 203° F.
Seite 72 - Antimony is a bright bluish-white coloured metal crystallizing in rhombohedrons, isomorphous with arsenic. It is very brittle, and can be powdered in a mortar ; it melts at 450°, and may be distilled at a white heat in an atmosphere of hydrogen. Antimony undergoes no alteration in the air at ordinary temperatures, but rapidly oxidizes if exposed to air when melted, and, if heated more strongly, it takes fire and burns with a white flame, giving off dense white funies of antimony trioxide.
Seite 157 - ... of the sower over soil previously prepared by the plough. This is the most ancient mode. In modern times the plan of drilling or dibbling has been adopted ; that is, depositing the seed in holes, formed in straight furrows at regular intervals. When wheat is crushed between the stones of the mill, it is separated into two parts, the bran and the flour. The bran is the outside harder part or...
Seite 121 - ... to 72 per cent ; oatmeal, 59 per cent ; ryemeal, 61 per cent; barley-meal, 67 per cent ; maize, 81 per cent ; rice, 83 to 85 per cent ; and it occurs in even larger proportions in arrowroot, sago, and tapioca. In a state of health, the proper diet consists in the due admixture of the albuminous, saccharine (or starchy), oleaginous, and saline groups ; but in certain forms of disease, an excess or a diminution of the starchy element...
Seite 58 - ... communicating a green tint to a flame of hydrogen gas, which is passed over it, and it is one of the best conductors of heat and electricity. Copper does not oxidize either in pure dry or moist air at ordinary temperatures, but if heated to redness in the air, it rapidly oxidizes to scales of copper oxide.
Seite 77 - ... 2. Soda-Ash Process. — This process consists (1) in the preparation of sodium carbonate, and (2) in the separation and purification of the same. The first chemical change which the salt-cake undergoes in its passage to soda-ash is its reduction to sulphide, by heating it with powdered coal or slack : — Na2SO4 + C4 = Na2S + 4 CO.
Seite 126 - CnH4O10,2HO, is usually seen in the form of colourless, transparent, oblique, rhombic prisms, which are not affected by the action of the air, have an agreeable acid taste, and are soluble in water and alcohol. The crystals when gently warmed become strongly electric, the opposite sides of the crystals exhibiting the opposite forms of electricity. On heating tartaric acid to about...
Seite 107 - Faraday has roughly estimated that the amount of oxygen required daily to supply the lungs of the human race is at least one thousand millions of pounds ; that required for the respiration of the lower animals is at least twice as much as this...
Seite 37 - ... madder or litmus, in a bottle of dry chlorine, and no change of colour takes place, even after the lapse of many weeks : if, however, a few drops of water are added, the colouring matter is immediately destroyed, and the cotton or paper is bleached. Here the chlorine combines with the hydrogen of the water, and the oxygen at the moment of its liberation (when it is said to be nascent) combines with the vegetable colouring matters, forming compounds destitute of colour. Ordinary free oxygen has...
Seite 126 - ... water. The exactness of this dilution is of the greatest importance to the success of the results. The dilute acid must not be used immediately after mixing, but must be suffered to cool to the ordinary temperature ; without attention to these apparently trifling points, the operator will not succeed. The alteration which takes place in the paper is of a very remarkable kind. No chemical change is effected, nor is the weight increased ; but it appears that a molecular change takes place, and...

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