AVENTURINE, or Avanturine, a variety of quartz containing spangles of mica or scales of iron-oxide, which confer brilliancy on the stone. It is found chiefly in the Ural Mountains, and is cut for ornamental purposes at Ekaterinburg. Some of the Siberian aventurine, like that of the vase given by Nicholas I. to Sir R. Murchison, in 1843, is a micaceous iron-stained quartz, of but little beauty. Most aventurine is of reddish brown or yellow colour, but a green variety, containing scales of fuchsite or chrome-mica, is also known. This green aventurine, highly valued by the Chinese, is said to occur in the Bellary district in India.
Aventurine felspar, known also as Sun-stone (q.v.) is found principally at Tvedestrand in south Norway, and is a variety of oligoclase enclosing micaceous scales of haematite. Other kinds of felspar, even orthoclase, may however also show the aventurine appearance. Both plagioclastic and orthoclastic aventurine occur at several localities in the United States.
The mineral aventurine takes its name from the well-known aventurine-glass of Venice. This is a reddish brown glass with gold-like spangles, more brilliant than most of the natural stone. The story runs that this kind of glass was originally made accidentally at Murano by a workman, who let some copper filings fall into the molten “metal,” whence the product was called avventurino. From the Murano glass the name passed to the mineral, which displayed a rather similar appearance. (F. W. R.*)
AVENUE (the past participle feminine of Fr. avenir, to come to), a way of approach; more particularly, the chief entrance-road to a country house, with rows of trees on each side; the trees themselves are said to form the avenue. In modern times the word has been much used as a name for streets in towns, whether with or without trees, such as Fifth Avenue in New York, or Shaftesbury Avenue in London.
AVENZOAR, or Abumeron [Abū Merwān ‛Abdal-Malik ibn Zuhr], Arabian physician, who flourished at the beginning of the 12th century, was born at Seville, where he exercised his profession with great reputation. His ancestors had been celebrated as physicians for several generations, and his son was afterwards held by the Arabians to be even more eminent in his profession than Avenzoar himself. He was a contemporary of Averroes, who, according to Leo Africanus, heard his lectures, and learned physic of him. He belonged, in many respects, to the Dogmatists or Rational School, rather than to the Empirics. He was a great admirer of Galen; and in his writings he protests emphatically against quackery and the superstitious remedies of the astrologers. He shows no inconsiderable knowledge of anatomy in his remarkable description of inflammation and abscess of the mediastinum in his own person, and its diagnosis from common pleuritis as well as from abscess and dropsy of the pericardium. In cases of obstruction or of palsy of the gullet, his three modes of treatment are ingenious. He proposes to support the strength by placing the patient in a tepid bath of nutritious liquids, that might enter by cutaneous imbibition, but does not recommend this. He speaks more favourably of the introduction of food into the stomach by a silver tube; and he strongly recommends the use of nutritive enemata. From his writings it would appear that the offices of physician, surgeon and apothecary were already considered as distinct professions. He wrote a book entitled The Method of Preparing Medicines and Diet, which was translated into Hebrew in the year 1280, and thence into Latin by Paravicius, whose version, first printed at Venice, 1490, has passed through several editions.
AVERAGE, a term found in two main senses. (1) The first, which occurs in old law, is from a Law-Latin averagium, and is connected with the Domesday Book avera, the “day's work which the king's tenants gave to the sheriff”; it is supposed to be a form of the O. Fr. ovre (œuvre), work, affected by aver, the O. Eng. word for cattle or property, but the etymology is uncertain. As meaning some form of feudal service rendered by tenants to their superiors, it survived for a long time in the Scottish phrase “arriage and carriage,” this form of the word being due to a contraction into “arage.” (2) The second word, which represents the modern usages, is also uncertain in its derivation, but corresponded with the Fr. avarie, and was early spelt “averays,” recurring also as “avaria,” “averia,” and meaning a certain tax on goods, and then more precisely in maritime law any charge additional to “freight” (see Affreightment), payable by the owner of goods sent by ship. Hence the modern employment of the term for particular and general average (see below) in marine insurance. The essential of equitable distribution, involved in this sense, was transferred to give the word “average” its more colloquial meaning of an equalization of amount, or medium among various quantities, or nearest common rate or figure. (For a discussion of the etymology, see the New English Dictionary, especially the concluding note with reference to authorities.)
In Shipping.—Average, in modern law, is the term used in maritime commerce to signify damages or expenses resulting from the accidents of navigation. Average is either general or particular. General average arises when sacrifices have been made, or expenditures incurred, for the preservation of the ship, cargo and freight, from some peril of the sea or from its effects. It implies a subsequent contribution, from all the parties concerned, rateably to the values of their respective interests, to make good the loss thus occasioned. Particular average signifies the damage or partial loss happening to the ship, goods, or freight by some fortuitous or unavoidable accident. It is borne by the parties to whose property the misfortune happens or by their insurers. The term average originally meant what is now distinguished as general average; and the expression “particular average,” although not strictly accurate, came to be afterwards used for the convenience of distinguishing those damages or partial losses for which no general contribution could be claimed.
Although nothing can be more simple than the fundamental principle of general average, that a loss incurred for the advantage of all the coadventurers should be made good by them all in equitable proportion to their stakes in the adventure, the application of this principle to the varied and complicated cases which occur in the course of maritime commerce has given rise to many diversities of usage at different periods and in different countries. It is soon discovered that the principle cannot be applied in any settled or consistent manner unless by the aid of rules of a technical and sometimes of a seemingly arbitrary character. The difficulty, which at one time seemed nearly insuperable, of bringing together the rules in force in the several maritime countries, has been to a large extent overcome—not by legislation but by framing a set of rules covering the principal points of difference in such a manner as to satisfy, on the whole, those who are practically concerned, and to lead them to adopt these History of the York-Antwerp rules. rules in their contracts of affreightment and contracts of insurance (see Insurance: Marine). The honour of the achievement belongs to a small number of men who recognized the need of uniformity. The work began in May 1860 at the congress held at Glasgow, under the presidency of Lord Brougham, assisted by Lord Neaves. Further congresses were held in London (1862), and at York (1864), when a body of rules known as the “York Rules” was agreed to. There the matter stood, until it was taken up by the “Association for the Reform and Codification of the Law of Nations” at conferences held at the Hague (1875), Bremen (1876) and Antwerp (1877). Some changes were made in the “York Rules”; and so altered, the body of rules was adopted at the last-named conference, and was styled the “York and Antwerp (or York-Antwerp) Rules.” The value of these rules was quickly perceived, and practical use of them followed. But they proved to be insufficient, or unsatisfactory, on some points; and again, in the autumn of 1890, a conference on the subject was held, this time at Liverpool, by the same Association, under the able presidency of Dr F. Sieveking, president of the Hanseatic High Court of Appeal at Hamburg. Important changes were then made, carrying further certain departures from English law, already apparent in the earlier rules, in favour of views prevailing upon the continent of Europe and in the United States. The new rules were styled the York-