A dictionary of chemistry. (Second, Third suppl.).

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Longman, Green, Roberts & Green, 1872 - Chemistry
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Page 477 - ... may be regarded as proportionate to the amount of force developed within the shortest period of time by that detonation, the latter being, in fact, analogous in its operation to that of a blow from a hammer, or of the impact of a projectile. Several remarkable results of an exceptional character have...
Page 393 - ... forms of the same condition of matter, and may be made to pass into one another by a series of gradations so gentle that the passage shall nowhere present any interruption or breach of continuity. From carbonic acid as a perfect gas to carbonic acid as a perfect liquid, the transition we have seen may be accomplished by a continuous process, and the gas and liquid are only distant stages of a long series of continuous physical changes.
Page 477 - ... those vibrations, either determine the explosion of that substance, or at any rate greatly aid the disturbing effect of mechanical force suddenly applied, while, in the instance of another explosion, which...
Page 128 - ... and drawn up on to a moistened strip of one square centimetre of filter-paper. If the paper is then burnt, being held with the platinum forceps, or, better, between two rings of fine platinum wire, the sample remains as a coherent crust, which now may without difficulty be heated in the flame. If the substance requires to be heated in the flame for a long period, the holder (fig.
Page 403 - Schaller prepares this acid by precipitating the aqueous extract of cochineal with neutral lead acetate, slightly acidulated with acetic acid ; decomposing the washed precipitate with sulphuric acid, again precipitating the filtrate with lead acetate, and decomposing the precipitate with sulphuric acid, avoiding an excess ; then precipitating a third time, and decomposing the precipitate with hydrogen sulphide. The filtered solution is evaporated to dryness ; the residue...
Page 132 - The fine asbestos-thread with the sample of substance is held on the glass tube (J) before the lamp so that it is placed at the height of the middle of the upper reducing flame, and the test-tube fixed so that the lowest point is just above the end of the asbestos-thread. If the lamp be now pushed under the test-tube, the substance and the asbestos-thread are in the reducing flame.
Page 477 - ... used as the exploding agent. An experimental comparison of the mechanical force exerted by different explosive compounds, and by the same compound employed in different ways, has shown that the remarkable power...
Page 476 - ... in such a way that chemical decomposition is established in some portion of the mass, and is favoured by the continued application of heat to that part. Under these circumstances, the chemical change proceeds with very rapidly accelerating violence, and the sudden transformation into gaseous products of the heated portion eventually results, a transformation which is instantly communicated...
Page 476 - ... almost without flame, to inflame with great rapidity, but without development of great explosive force, or to exercise a violent destructive action, according as the mode of applying heat, the circumstances attending such application of heat, and the mechanical condition of the explosive agent, are modified*.
Page 128 - ... emission. The following phenomena are observed when a sample of a substance is heated : 1. Emission of Light. — The emissive power of substances is ascertained by placing them on the platinum wire in the hottest part of the flame. The sample is of weak emissive power when it is less luminous than the platinum wire; of a mean emissive power when both appear about equally luminous; and of strong emissive power when the intensity of the light which it emits is greater than that from the platinum....

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