The quantity of alcohol present in an aqueous solution is determined by a comparison of its specific gravity with standard tables, or directly by the use of an alcoholometer, which is a hydrometer graduated so as to read per cents by weight (degrees according to Richter) or volume per cents (degrees according to Tralles).
It is infusible before the gas blowpipe, but in the oxyhydrogen flame fuses to a clear colourless glass, which has a hardness of 5 and specific gravity 2.2.
The specific gravity of cast gold varies from 18.29 to 19.37, and by compression between dies the specific gravity may be raised from 19.37 to 19.41; by annealing, however, the previous density is to some extent recovered, as it is then found to be 19.40.
To illuminating oil or kerosene a series of tests is applied in order that the colour, odour, specific gravity and flash-point or fire-test may be recorded.
Besides the determination of salinity by titration of the chlorides, the method of determination by the specific gravity of the sea-water is still often used.
The preface treats of Greek sciences, geometry, the discovery of specific gravity by Archimedes, and other discoveries of the Greeks, and of Romans of his time who have vied with the Greeks -- Lucretius in his poem De Rerum Natura, Cicero in rhetoric, and Varro in philology, as shown by his De Lingua Latina.
In the amorphous state it is a dull green, almost infusible powder, but as obtained from chromium oxychloride it is deposited in the form of dark green hexagonal crystals of specific gravity 5 2.
Pure amorphous boron is a chestnut-coloured powder of specific gravity 2.45; it sublimes in the electric arc, is totally unaffected by air at ordinary temperatures, and burns on strong ignition with production of the oxide B 2 0 3 and the nitride BN.
It will have, when freshly burned, a specific gravity not lower than 3.15, and briquettes made from it and kept in water will possess a tensile strength of 400-500 lb per sq.
Red lead or triplumbic tetroxide, Pb304, is a scarlet crystalline powder of specific gravity 8.6-9.1, obtained by roasting very finely divided pure massicot or lead carbonate; the brightness of the colour depends in a great measure on the roasting.