AMBER, one of the most important and valuable of the fossil resins. It is one of the oxygenated hydrocarbons and its mineralogical name, succinite, emphasizes one of its distin guishing characteristics, namely, the presence of from 5 to 8 per cent of succinic acid. Its com position is represented by the formula C4•11..04. It occurs in irregular masses, usually of small size but sometimes weighing up to 15 or 18 pounds. It has a yellow color, resinous lustre and conchoidal fracture. Its hardness is 2 to 2.5 and specific gravity 1.05 to 1.1. Along the shores of the Baltic Sea, especially in East Prussia, mining for amber has been carried on for two centuries. In this region shafts are sunk through a superficial stratum of marl and sand, a bed of lignite with light sands and gray clays, and finally a layer of green-sand, 50 to 60 feet thick. All of these strata contain amber, but in the lower portion of the green-sand there is a stratum four to five feet thick of °blue earth" in which amber nodules occur so abun dantly that 50 or 60 square rods yield several thousand pounds. This °blue earth" stratum extends out under the sea and there the amber is freed and cast upon the shores by the waves, especially after the autumnal storms. Small quantities are found in Great Britain, on the coasts of Sicily and the Adriatic. in various parts of Europe, in Siberia, Greenland and in the United States.
Pliny declared amber to be °an exudation from trees of the pine family," a conjecture that proves to be correct. The fact that it
was at one time fluid or nearly so is established by its occasional inclusion of insects; and its antiquity is also established by the fact that most of the species of insects so included are now extinct.
Amber becomes strongly electrified when rubbed, and the power that it then possesses, of attracting light bodies to itself, was proba bly considered by the ancients to be the out ward sign of the mysterious virtues that they attributed to the mineral. It was greatly es teemed for ornaments and charms, and Pliny says that among women it had been so highly valued as an object of luxury that a very di minutive human effigy, made of amber, had been known to sell at a higher price than living men, even in stout and vigorous health." He also says that a necklace of amber beads was con sidered to protect the wearer from secret poisons, and to be efficacious as a counter-charm against sorceries and witchcraft. In the time of Nero an expedition sent from Rome to the Prussian amber-beds returned with 13,000 pounds of the precious substance.
In modern times amber is chiefly used for the manufacture of mouthpieces for tobacco pipes and for the preparation of a kind of var nish. The attractive power exhibited by amber when rubbed was the first electrical phenome non observed by man, and the word °electricity" was derived from electrum, the Greek name for amber.