Prop., &c. Melts without decomposition, and, when pure, burns without residue. It is distinguished from other varieties of bitumen by its more difficult fusibility, and by its fracture being clean, conchoidal, and vitreous. Distilled by itself it yields about 36% of a peculiar bituminous oil (crude PETROLENE), together with combustible gases, traces of ammonia and water. To anhydrous alcohol it yields 5% of a yellow resin, soluble in rectified spirit and ether; by digesting the residuum in ether, a further 70% of a brownish-black resin is obtained, which is freely soluble in the volatile oils and in about 5 times its weight of mineral naphtha. The portion (25%) left undissolved by ether is very soluble in the oils of turpentine and petroleum. These three resinous principles dissolve altogether, when digested, in the oils of anise, rosemary, and turpentine, and in the fixed oils. (John.) According to others, asphaltum consists almost entirely of asphaltene. (Boussingault.) Paranaphthaline has been found in some varieties. (M. Laurent.) Average sp. gr. 1 to 1·68. By friction it affords negative electricity. It is soluble in oil of turpentine, benzole, mineral and coal-tar naphtha, the fixed oils, solutions of the caustic alkalies, and several other liquids, by the aid of heat.
Sources. That of commerce is chiefly obtained from the shores of the Dead Sea; but much of that of the shops is a spurious article of the most worthless character. A short time since some specimens of the purest and most beautiful description, from the Great Bitumen Lake of Trinidad, were given us by our respected and venerable friend, the late Earl of Dundonald, who stated that the supply of both liquid and indurated bitumens, of every grade of quality, was unlimited from that source; but that owing to injudicious importations of inferior kinds (those most easily shipped), a prejudice had been created against them in the London market. Our personal investigations have since confirmed the accuracy of these statements.
Uses. The finer varieties are chiefly used as a ‘glazing colour’ by artists, and in the manufacture of black varnishes and japans. The inferior kinds are applied to the same purposes as ordinary solid bitumen. The Egyptians used it in embalming under the name of MU′MIA; and the Babylonian builders are said to have employed it, as a cement, in lieu of mortar. It is, however, doubtful whether the hard semi-vitreous variety of bitumen, properly termed ‘asphaltum,’ was that which was thus employed; its present hardness being probably due to time. As a medicine it is stimulant; and it was formerly used as an ingredient in certain plasters and ointments. See Bitumen, Pitch, &c. A mixture of asphalt, chalk, sand, ground sandstone, &c., is used as a pavement for making water-tight tanks and covers, as a coating for gas and water pipes, and for various other similar purposes. Sometimes the pitchy residue obtained by distilling off the more volatile portions of gas tar is employed to replace the asphalt in the foregoing mixture; the product is called artificial or gas-tar asphalt.
Asphaltum, Facti′′tious (-tĭsh-′ŭs). Syn. Asphal′tum facti′′tium, L. That of the shops,
when not an inferior kind of true asphaltum, is commonly made from the bottoms of Barbadoes tar, and other mineral bitumens, by heating them until quite hard. Sometimes a little Scio turpentine, balsam of copaiba, or even common resin, is added. Colour, hardness, &c., inferior to those of native asphaltum.
Asphaltum, Liq′uid. Syn. Prepared’ asphaltum; Asphal′tum liq′uidum, L. Prep. 1. Scio turpentine, 2 oz.; melt; add asphaltum (in powder), 1 oz.; mix, cool a little, and reduce with hot oil of turpentine.
2. (Wilson’s.) Asphaltum, 1⁄2 lb.; melt; add of hot balsam of copaiba, 1 lb.; and, when mixed, thin it with hot oil of turpentine. Both are used as ‘black japan’ or ‘varnish,’ and as a ‘glazing colour’ by artists.
ASPHYX′IA (-fĭk′-sh′ă; -fĭks′-e-ă‡). [L., Gr.] Syn. Asphyx′y‡ (-e), Eng.; Asphyxie, Fr.; Pulslosigkeit, Scheintod, Gr. Literally, absence of pulse; hence, a fainting fit; apparent lifelessness. Its use is now generally confined to a suspension of vitality from some cause interrupting respiration, but in which life is not actually extinct, and may, under favorable circumstances, be revived.
Asphyxia is commonly divided into four varieties by nosologists:—
1. Asphyxia algida:—Cause. Exposure to intense cold.—Symp. Countenance pale, livid, and shrivelled; limbs rigid.