ASPHALTUM is one of the varieties of bitumen, arising from the decomposition of vegetable matter. It occurs massive, of a dark brown or black colour,with a conchoidal fracture, and a resinous lustre. It is opaque, and exceedingly brittle at a low temperature, but softens and fuses by the application of heat. It is insoluble in alcohol, but soluble in about five times its weight of naptha, with which it forms a good and useful varnish. Its combustion is rapid and brilliant, with the production of the bituminous odour.
It is found in many countries, bat most abundantly on the shores, or floating on the surface of the Dead Sea ; at Hit, above Baby lon, on the Euphrates ; and near the Tigris. In Trinidad in the West Indies it fills a basin of three miles in circumference and of unknown depth. The Earl of Dundonald has recently (1849) made some experiments on the avail ability of the Barhadoes asphaltum for fuel ; he mixed it with coal (two parts of asphaltum to one of coals) and found that it made a good fuel for steamers ; he also devised a form of furnace for burning it. There is a pitch-spring in Zante, which is known to have been at work for above 2000 years. Asphaltum is the prin cipal colouring matter of the dark indurated marl, or shale, which is found in coal districts.
A liquid asphaltum, useful as a black japan or varnish, is made by melting asphaltum with Scio turpentine and oil of turpentine ; or sub stituting balsam of copaiba for the Scio tur pentine.
Counterfeit asphaltum is occasionally sub stituted for the real ; it consists of the dregs of Barbadoes tar, heated until quite hard.
ASS. This ill-used and ill-appreciated ani mal (in England, at least) takes an important part in oriental travelling and commerce. The
fine Arabian asses are used only for the sad dle, and are imported in great numbers into Persia, where, according to Charffin, they are frequently sold for 400 livres ; they are taught a kind of easy ambling pace, are richly capa risoned, and used only by the rich and luxu rious nobles. A fine breed, of Arab lineage, used exclusively for the saddle, exists in Syria; —a small spirited and graceful ldnd is also found in Syria, upon which the ladies ride from preference; and besides this there is a stout breed fitted for ordinary labour. Another breed, that of Damascus, is characterized by the length of its body and of its ears; it is much employed by the bakers of Damascus in carrying flour and brushwood. The ordinary asses of Persia are strong, but in other respects not to be compared to those of Arabia. As we proceed farther eastward the ass degene rates, and in India it is -very small, of inferior qualities, and used only by the people of the lowest caste. The finest asses of Europe are those of Malta and Spain. Italy also possesses a superior breed ; and the same remark ap plies to some parts of France, as Le Poitou and Le Mirebalais.
It is a curious example of the extent to which nature is imitated by man, either for honest or dishonest purposes, that artificial asses' milk is manufactured. One recipe com prises new cow's milk, sugar-candy, ground rice, and eringo root ; while another com prises water, hartshorn shavings, lump sugar, new mi k, and syrup of tolu.