AMBER, a fossil resin much used for the manufacture of ornamental objects. The name comes from the Arab. anbar, probably through the Spanish, but this word referred originally to ambergris, which is an animal substance quite distinct from yellow amber. True amber has sometimes been called karabe, a word of oriental derivation signifying " that which attracts straw," in allusion to the power which amber possesses of acquiring an electric charge by friction. This property, first recorded by Thales of Miletus, suggested the word " electricity," from the Greek, AEKrpov, a name applied, however, not only to amber but also to an alloy of gold and silver. By Latin writers amber is variously called electrum, sucinum (succinum), and glaesum or glesum. The Hebrew hashmal seems to have been amber. Amber is not homogeneous in composition, but consists of several resinous bodies more or less soluble in alcohol, ether and chloroform, associated with an insoluble bituminous substance. The average composition of amber leads to the general formula C1oH160. Heated rather below 30o° C. amber suffers decomposition, yielding an " oil of amber," and leaving a black residue which is known as " amber colophony," or " amber pitch "; this forms, when dissolved in oil of turpentine or in linseed oil, "amber varnish " or " amber lac." True amber yields on dry distillation succinic acid, the pro-portion varying from about 3 to 8%, and being greatest in the pale opaque or " bony " varieties. The aromatic and irritating fumes emitted by burning amber are mainly due to this acid. True Baltic amber is distinguished by its yield of succinic acid, for many of the other fossil resins which are often termed amber contain either none of it, or only a very small proportion; hence the name " succinite" proposed by Professor J. D. Dana, and now commonly used in scientific writings as a specific term for the real Prussian amber. Succinite has a hardness between 2 and 3, which is rather greater than that of many other fossil resins. Its specific gravity varies from 1.05 to 1.10. The Baltic amber or succinite is found as irregular nodules in a marine glauconitic sand, known as " blue earth," occurring in the Lower Oligocene strata of Samland in East Prussia, where it is now systematically mined. It appears, however, to have been partly derived from yet earlier. Tertiary deposits (Eocene); and it occurs also as a derivative mineral in later formations, such as the drift. Relics of an abundant flora occur in association with the amber, suggesting relations with the flora of Eastern Asia and the southern part of North America. H. R. Goppert named the common amber-yielding pine of the Baltic forests Pinites succinifer, but as the wood, according to some authorities, does not seem to differ from that of the existing genus it has been also called Pinus succinifera. It is improbable, however, that the production of amber was limited to a single species; and indeed a large number of conifers belonging to different genera are represented in the amber-flora. The resin contains, in addition to the beautifully preserved plant-structures, numerous remains of insects, spiders, annelids, crustaceans and other small organisms which became enveloped while the exudation was fluid. In most cases the organic structure has disappeared, leaving only a cavity, with perhaps a trace of chitin. Even hair and feathers have occasionally been represented among the enclosures. Fragments of wood not infrequently occur, with the tissues well-preserved by impregnation with the resin; while leaves, flowers and fruits are occasionally found in marvellous perfection. Sometimes the amber retains the form of drops and stalactites, just as it exuded from the ducts and receptacles of the injured trees. The abnormal development of resin has been called " succinosis." Impurities are often present, especially when the resin dropped on to the ground, so that the material may be useless except for varnish-making, whence the impure amber is called firniss. Enclosures of pyrites may give a bluish colour to amber. The so-called " black amber " is only a kind of jet. " Bony amber " owes its cloudy opacity to minute bubbles in the interior of the resin. Although amber is found along the shores of a large part of the Baltic and the North Sea, the great amber-producing country is the promontory of Samland. Pieces of amber torn from the sea-floor are cast up by the waves, and collected at ebb-tide. Sometimes the searchers wade into the sea, furnished with nets at the end of long poles, by means of which they drag in the sea-weed containing entangled masses of amber; or they dredge from boats in shallow water and rake up amber from between the boulders. Divers have been employed to collect amber from the deeper waters.