AMBER.
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parts of plants (as the wood, leaves, flowers, and fruit). According toSir D. Brewster ( Edinb. Philosoph . Journ. vol. ii.) its optical propertiesare those of an indurated vegetable juice. From these circumstances, aswell as from its chemical composition, amber is supposed to have been aresinous exudation from some tree. Now as the wood, leaves, blossoms,and fruit of some coniferous plant are found in amber, this plant hasbeen supposed to be the amber tree : and a microscopic examination ofthe wood leads to the conclusion that the amber tree is a species, thoughprobably an extinct one, of the genus Pinus , closely allied to P. balsamea.(Hope, On Succinic Insects, in Trans. Entom. Soc. vols. i. and ii.)
Properties. —It occurs in irregular - shaped pieces, usually flat andsomewhat rounded at the sides. Its colour is yellowish white ( sued-num album), yellow {s. citrinum ), or reddish (.9. rubrum). It is usuallytranslucent, sometimes opaque or transparent: it is tasteless and odour-less. Its sp. gr. is about 1'07. It is brittle, yields readily to the lsnife,has a conclioidal vitreous or resinous fracture, and becomes negativelyelectrical by friction : it contains various insects which, apparently,must have become entangled in it while it was soft and viscid. (For anaccount of these, consult Mr. Hope’s paper before quoted; also Bur-meister’s Manual of Entomology, p. 574).
Heated in the air, amber fuses at about 541° F., their inflames, and bumswith a yellow flame, emitting a peculiar odour, and leaving behind alight shiny black coal. It cannot be fused without undergoing somechemical change. It evolves water, volatile oil, and succinic acid : theresidual mass is termed colophonium succini. By destructive distillationin a retort or alembic, amber yields first an acid liquor (which containssuccinic and acetic acids), then some succinic acid deposits in the neckof the retort, and an empyreumatic oil ( oleum succini) comes over, at firstthin and yellowish, afterw ards brown and thick : towards the end of theoperation, a yellow light sublimate is observed in the neck of the retort;this is called, by Berzelius , crystallized pyretine; by Vogel, volatile resinof amber; by Gmelin, amber-camphor. An inflammable gas is evolvedduring the whole time of the operation.
Composition. —The ultimate constituents of amber are carbon,hydrogen, and oxygen. The proximate principles are a volatile oil, tworesins, succinic acid, and a bituminous substance.
Ultimate Constituents.
Proximate Constituents.
Drassier.
Ure.
Carbon . .
. 80-59 .
70-68
Volatile Oil
Hydrogen .
. 7 - 31 .
11-62
Two Resins
Oxygen . .
. 6-73 .
7-77
Succinic Acid
Ashes (silica, lime, and alumina) 3*27
Bitumen
Amber . . .
.97-90
90-07
Amber.
The volatile oil has a strong but agreeable odour. The resins aresoluble in both alcohol and ether: if an alcoholic solution of the tworesins be prepared by heat, and then allowed to cool, one of the resinsdeposits. Succinic acid is white and crystalline, soluble in water,scarcely so in cold, but more so in boiling, alcohol. It is distinguishedfrom benzoic acid by its insolubility in oil of turpentine. Succinate ofammonia throws down a reddish precipitate with the persalts of iron.The bituminous matter constitutes the principal part of amber: it is