AMBER, a carbonaceous mineral which occurs in beds of lignite, in Greenland, Prussia, France, Switzerland, and some other countries. The greater portion of it comes from the southern coasts of the Baltic Sca, where it is thrown up between Konigsberg and Memel. (Ber zelius, Trait6 do Chimie,' vi. 589.) It is also stated (`Annales do Chimie,' xvi. 215) that it is obtained by mining at a distance of 200 feet from the sea, and at a depth of about 100 feet, and is found iu small cavities. It is occasionally met with (Aikin's Diet. of Chemistry,' i. 57) in the gravel beds near London, in which case it is merely an alluvial deposit. Amber occurs generally in small pieces, which are sometimes colourless, frequently light yellow or and very commonly translucent ; two large masses have, however, been found, one of them weighing upwards of thirteen pounds, and tho other more than eighteen.
Amber is rather harder than common resins, which it resembles in several properties : it is susceptible of a good polish, and when rubbed becomes electrical; indeed the word electricity is derived from iiteterpov, the Greek name for amber. Its density varies from to 1.070. \\lien bruised it exhales a slight aromatic odour ; and when heated to 448° Fahrenheit it melts, inflames, burns with a bright flame, and emits a smell which is not disagreeable.
The subject of the origin of amber is one which has been much discussed. According to Berzelius (' Chimie,' vi. 589), it was origi nally a resin dissolved in a volatile oil or natural balsam. The proofs
of this opinion arc, he conceives, numerous. Thus, it has often the impression of the branches and bark upon which it has flowed and solidified ; it often contains insects, some of which are so delicately formed, that they could not have occurred except in a very fluid mass. Dr. Brewster (` Edinburgh Phil. Journal,' iv. 332) concludes, from an examination of the optical properties of amber, that it is an indurated vegetable juice.
Amber consists of a mixture of a volatile oil, two resins soluble in alcohol and in ether, suceinic acid, and a bituminous body that resists the action of all solvents, and which is the principal part of amber.
Water does not act upon this substance ; it does not even dissolve any of the succinie acid. Alcohol takes up a soft, yellow, limpid resin. Cold concentrated sulphuric acid dissolves amber ; the solution has a brown colour, and when water is added to it, the greater part of the amber is precipitated. Nitric acid converts it into a resinous substance, and dissolves it totally.
The ashes consist of lime, silica, and alumina. This analysis can only be considered as an approximation.
Amber is emploped for ornamental purposes, in tho manufacture of necklaces, &c. It is used also for preparing amber-varnish, for obtaining a peculiar oil used in medicine, and it yields succinie acid ernyloyed in chemical investigations.