Page:Encyclopædia Britannica, Ninth Edition, v. 2.djvu/782

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716
ASP—ASP

marschen-; in Holstein, &c. These bituminous stones contain from 7 or 8 to about 20 per cent, of asphalt in their composition, that from Val de Travers being richest in bituminous matter and of most value in its industrial applications. The asphalt beds of the Val de Travers were first discovered and utilised by Eirinus, a Greek physician, in 1712, who recommended the material as being " peculiarly suitable for covering all kinds of constructions ; to protect wood and stone work against decay, worms, and the ravages of time, rendering them almost indestructible even when exposed to wind, wet, and extreme variations of temperature." Eirinus was aware that asphaltic mortar had been used in the building of ancient Babylon, and he himself succeeded in using it with great effect for the lining of cisterns and walls as a cementing material, and for the flooring of warehouses, <fcc. After some time the material fell into disuse ; the quarries of Val de Travers were even forgotten, and it was not till the year 1 832 that the material was again prominently and successfully re- introduced, the credit on this occasion being due to the Count Sassenay. Under his direction asphaltic stone came to be extensively used in France for pavements and roadways, and for protecting floors and walls from the effects of damp. From France the application of the material for such purposes extended to other countries, and there is now a wide-spread demand for asphaltic pave ments. Two principal methods are adopted in laying asphalt pavements, 1st, the mastic process ; 2d, the hot compressed process. The mastic process is essentially as follows : The bed of the road-way is prepared with a smooth level foundation of concrete, which must be thoroughly dry before the application of the asphalt. The mastic is prepared for application by heating the asphaltic stone and breaking it into small pieces, which are then melted up with a quantity of mineral tar, to which some sand is added. The molten mass is then poured over a section of the prepared concrete uniformly to the requisite depth ; the surface is smoothed, and covered with a coating of fine sand which is stamped into the asphalt. The proportions of tar and sand used vary with the composition of the asphaltic stone employed and the position occupied by the pavement The other mode of laying pavements, now extensively adopted, consists in spreading hot powdered asphaltic stone on the prepared surface, which is then heavily pressed till it forms a homogeneous elastic coating. Roadways so prepared are very durable, smooth, cleanly, and noiseless, but the material is not well adapted for other than level streets on account of the difficulty of foothold. Complaints are also made against such pave ment, to the effect that accidents to horses from slipping and falling are much more frequent than is the case on ordinary stone pavement. An artificial asphalt is pre pared by boiling up the pitch of gas-tar with chalk and sand, but such a substitute, though much cheaper, has not the durability of the natural compound. Gas-tar asphalt is also applied for other purposes in which the natural product is used. Asphalt was used by the ancient Egyptians in their process of embalming bodies. It is the principal ingredient in black Japan varnish. It is distilled in large quantities for the illuminating and lubricating oil which it yields, but the bituminous shales from which paraffin and paraffin oils are distilled must not be con founded with asphaltic deposits. It is also used for preparing roofing felts ; paper water-proofed with asphalt has been used, and drain-pipes of compressed asphalted

paper are manufactured.

ASPHYXIA (α priv., [ Greek ], a pulse), a term in medi cine which, though literally signifying loss of pulsation, is applied to describe the arrestment of the function of respiration from some hindrance to the entrance of air into the lungs. (See Physiology and Medical Jurisprudence.)

ASPINWALL, or Colon, a city and free port on the northern coast of Panama, one of the united states of Colombia. It is built on the well-wooded coral island of Manzanilla, iulat. 9 22 53" N., and long. 79 52 58" W., owes its origin to the Panama Railway Company, who founded it (1850) for the convenience of their traffic, and derives its more usual name from W. H, Aspinwall, one of their principal shareholders. In spite of the unhealthiness of its situation, now, indeed, largely diminished, and the dangerous winds from the north to which it is at some seasons exposed, it has quite superseded the neighbouring port of Chagres, and become the centre of a considerable local trade. The banana, especially, is cultivated in the neighbourhood and largely exported to New York. The population, composed mainly of Jamaica and Spanish negroes, was stated at C500 in 1872. A telegraph line extends from Aspinwall to Kingston in Jamaica.

ASS, The DomesticAsinus vulgaris, Gray—differs chiefly from the horse in its smaller size, in the presence of

long hair, forming a tuft, only at the extremity of the tail, and in the absence of warts on its hind legs. Its fur, usually of a gray colour, is characteristically marked with a longi tudinal dorsal streak of a darker hue, with a similar streak across the shoulders, but white and black varieties also occur. The ass has been from time immemorial under the dominion of man, and it is doubtful whether the original wild stock is anywhere to be found at the present day, the specimens that have been described as wild being probably the descendants of individuals that have escaped from the domestic state. A wild variety of ass (Asinus tceniqptis), found in Abyssinia, has the long acute ears and the bray peculiar to the domestic kinds. It is said also to have cross bands on its legs, a feature occasionally met with in our tame breeds; and this fact has led Darwin and others to conclude that in the wild ass of Abyssinia the original of the domestic animal is to be found; the stripes which occasionally appear on the legs of the latter being regarded as instances of reversion to the ancestral type (Proceedings of Zool. Society, 1SG2). The marked aversion of the domestic ass to cross the smallest streamlet, an aversion which it shares with the camel, and the evident delight with which it rolls itself in the dust, seem to point to arid deserts as its original home. The ass has generally been the object of neglect and ill treatment; and attempts have seldom been made to improve the breed by select ing and matching the finer specimens. It has thus gradually sunk into the dull and obstinate creature which we are accustomed to see. Its reputation for stupidity is not, however, of recent origin. The ancient Egyptians hated it, and symbolised an ignorant person by the head and ears, and the Romans thought it a bad omen to meet an ass (Fosbrooke s Antiquities}. In the Middle Ages the Germans of Westphalia made the ass the symbol of St Thomas, the unbelieving apostle; and the boy who wa3 last to enter the school on St Thomas day was called the "Ass Thomas" (Gubernatis s Zoological Mythology, voL i p. 3G2). That the ass possesses qualities, which, if de veloped by careful selection and humane treatment, would make it a worthy companion of the horse as the servant of man, is seen in the too rare instances in which it has received proper attention. In Southern Europe especially in Spain, Italy, and Malta the ass is carefully bred, and has thus been greatly improved. No less than 200, it id said, is sometimes paid in Spain for a stallion ass. In the state of Kentucky, where mules are in great request as beasts of burden, asses, imported from the south of Europe, are reared with scrupulous care, and with such success, that from an average height of fourteen hands the Ken-