Page:Encyclopædia Britannica, Ninth Edition, v. 2.djvu/781

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whose secretary he acted for some time. His orations,

which are praised for their style, have been lost.

ASPEN TREE, called also the trembling-leaved poplar (Populus tremula), is a native of Britain, and is found generally in moist places, sometimes at a considerable elevation, 1GOO feet or more, in Scotland. It flowers in Britain in March and April. The name "trembling" is applied to it on account of the constant movement of the leaves even with a gentle breeze. This mobility depends on the leaves being suspended by leaf-stalks flattened laterally, and when subjected to a slight wind, by their friction on each other they give rise to a rustling sound. It is supposed that the mulberry trees (Becalm) mentioned in 1st Chronicles xiv. 14, 15, were really aspen trees. The wood of the tree is white, and is made use of by turners. In France sabots are made of it; and the charcoal made from the w r ood is used in the manufacture of gunpowder. The leaves are in some countries of Europe employed as food for cattle, sheep, and goats.

ASPENDUS (or, as the name appears on the more ancient coins, Estfendys), a city of Pamphylia, in Asia Minor, situated on an isolated hill near the river Eurymedon (Capri-sii) at the extremity of the plain of Perga. It was founded by a colony from Argos, five centuries before the Christian era, and attained to great prosperity, as is attested, not only by the statements of Greek and Roman writers, but also by the noble ruins that still occupy the site. Of these the most remarkable is the theatre, which is regarded as more perfect than any other in Asia Minor, requiring but little restoration to render it fit once more for its ancient use. In the first precinct there are twenty- one rows of seats, and in the second eighteen, nearly all of them entire. The date of the building is assigned by an inscription to the time of Antoninus and Lucius Verus. An aqueduct of magnificent proportions, built, like the theatre, of the silicious conglomerate of the neighbourhood, still stretches across the plain ; and the ruins of an agora and other erections are found on the hill. That the city Avas rich in valuable statues is mentioned by Cicero, who rhetorically accuses Yerus of having plundered it of them all. It only appears occasionally in ancient history, as when its inhabitants surprised and assassinated Thrasybu- lus, and again when they surrendered to Alexander ; but the populousness of the place is proved by the fact that it was able to furnish 4000 hoplites.

ASPER, Hans, a Swiss painter, was born in 1499 at Zurich, where he died on the 21st March 1571. He wrought in a great variety of styles, but excelled chiefly in flower and fruit pieces, and in portrait painting. Many of his pictures have perished, but his style may be judged from the illustrations to Gessner s llistoria Animalivm,for which he is said to have furnished the designs, and from portraits of Zwingle and his daughter Uegula Gwalter, which are preserved in the public library of Zurich. It has been usual to class Asper among the pupils and imi tators of Holbein, but an inspection of his works is suffi cient to show that this is a mistake. Though Asper was held in high reputation by his fellow-citizens, who elected him a member of the Great Council, and had a medal struck in his honour, he seems to have been frequently in embarrassed circumstances, and there is reason to believe that he died a pauper.

ASPHALT, or Asphaltum ([ Greek ], Aristotle, Bitumen, Pliny), the German Bergpech, or mineral pitch, so called from the Lacus Asphaltites or Dead Sea, where it was found in ancient times, is a product of the decomposition of vegetable and animal substances. It is usually found of a black or brownish-black col our, externally not unlike coal, but it varies in consistency from a bright pitchy condition, with a sharp conchoidal fracture, to thick viscid masses of mineral tar. Asphalt melts at or a little below the boiling point of water, and it burns with a rather smoky flame. It is regarded as the ultimate result of a series of changes which take place, under certain conditions, in organised mat ter, producing 1st, naphtha; 2d, petroleum; 3d, mineral tar ; and 4th, asphalt or hard bitumen. The whole of these substances merge into each other by insensible degrees, so that it is impossible to say at what point mineral tar ends and asphalt begins. Naphtha, which is the first of the series, is in some localities found flowing out of the earth as a clear, limpid, and colourless liquid. As such it is a mixture of hydrocarbons, some of which are very volatile and evaporate on exposure ; it takes up oxygen from the air, becomes brown and thick, and in this condition it is called petroleum. A continuation of the same process of evaporation and oxidation gradually transforms the material into mineral tar, and still later into solid glassy asphalt. Asphalts are very variable in composition, and their proximate constituents have not been subjected to a thorough examination. Traces of naphtha or light oils are usually found in them, and they always contain a per centage of the heavier hydrocarbons not vaporisable below boiling point. Resins soluble in alcohol, and solids, some soluble in ether, and some resisting the solvent action of both ether and alcohol, are found in varying porportions. According to Dana " asphalt may consist of either (1), unoxygenatecl, or (2), partly unoxygenated and partly oxygenated (the usual fact), or (3), solely of oxygenated hydrocarbons (very rarely, if ever, true in nature). The state of solidity is not proof that any part of the bitumen is oxygenated." Asphaltic deposits exist widely diffused throughout the world, more especially in tropical and sub tropical regions. It is found in a state of great purity in the interstices of the older rocks, but its occurrence is not characteristic of any particular formation or period. The most remarkable deposit of asphalt exists in Trinidad, where it forms a lake 99 acres in extent, and of unknown depth, intersected with rivulets of water. At two or three places on the surface of the lake an emission of semi fluid tar may still be seen in progress, accompanied with an evolution of sulphuretted hydrogen. At these points the substance is still soft and viscid, but by exposure it gra dually obtains the consistency of the rest of the mass. In addition to the lake deposit, asphalt occurs in the sur rounding country named La Brea, on account of this peculiarity in detached patches, or in sheets of consider able size, at one point protruding into the sea, and pieces of asphalt are frequently cast up on the neighbouring shore. A considerable quantity of a fine asphalt is also derived from Cuba under the name " Chapapote," or Mexican asphalt ; and from Caratambo in Peru, a very pure variety of high lustre is exported. The asphalt of the Dead Sea is more a tradition than a reality, it being now found there in very small quantities ; but the source of the supply of ancient Babylon, the fountains of Is, on a tributary of the Euphrates, still yields asphalt. It occurs in many localities throughout Europe, but not to any considerable extent. The following table gives the ultimate composition of specimens from several localities:—

Curbon. Ily Irocen. Oxyccn. Nitrogen. Asli. .Auvergne, Franco ...77 iH 7 i Cuba 82-34 9-10 6-25 1-91 0-40 Caxatambo, Peru ....SS Gu 9 C9 T05

Of greater importance industrially than simple asphalt

is asphalt stone, a limestone impregnated with bituminous matter, which occurs in large quantities at several European localities. The most valuable deposits are in the Val de Travers, cantwi of Neufchatel ; in the neighbourhood of Seyssel, department of Ain ; at Bechelbronn in Alsace,

Limmer near the city of Hanover, and Hiille in Dit-