SUCCINUM is a bituminous substance of a peculiar kind, the natural history of which has been already detailed. [Armen, in NAT. HIST. ply.] It is not now used in the crude state in medicine, but is employed to yield the oleum auecini, or oil of amber. This Is pro cured by the destructive distillation of amber, which is put into a glass, copper, or iron retort, fitted with a glass alembic properly lilted. A gentle heat is applied by means of a sand-bath, by which the amber is melted, and a little volatile nil passes over ; after thie the amber swells greatly, and the distillation proceeds rapidly. By this process three very distinct products are obtained, namely, impure suocinic acid, which adheres to the neck of the retort ; an acid liquid (called spiritus volatilis succini), in which auccinic and acetic acids exist mingled with empyreumatic oil ; and, lastly, the-volatile oil of amber, which is to bo separated from the acid liquid by careful pouring off. What remains in the retort is colophony of amber, which is used to make varnish.
The volatile oil thus obtained is impure, containing various pyrogenous ingredients, and requires repeated distillations to purify it. If in the third or fourth of these the process be interrupted when about two thirds only of the oil has passed into the receiver, there is obtained a volatile oil of a light yellow colour, a peculiar bituminous odour, and of the specific gravity If the distillation be continued too long, an empyreumatic oil is evolved, which gives to the other a coffee-brown hue; and this is the general appearance of rectified oil of amber. By some writers freshly prepared charcoal is directed to be put iuto the retort when the impure oil is to be distilled, but that is very improper, as by its means the pyrogenous principles, which it is the object of the rectification to separate, are very abundantly generated. The purest
oil has a sharp burning taste, an acid re-action, and on exposure to tho air becomes brown and inspissated. Various resinous matters sub stituted for amber may all be detected by the absence of succinic acid.
Volatile oil of amber probably contains a large portion of creasote, as may be inferred from the analogous action of nitric acid on it and on creosote. One part of rectified oil of amber, and three parts of moderately strong nitric acid, form a magma, which has the odour of musk, and is called artificial musk. Rectified oil of amber is sti mulating, anti-spasmodic, and rubefacieut. It is now little given internally, except in combination with ammonia, in the celebrated eau de-luce, for which the tinctura ammonite composita of the Pharma copoeia was a substitute, but now omitted. This is to be applied to the nostrils in fainting, hysteria, and epilepsy, or a very few drops diluted with water may be taken internally. Oil of amber is beneficially rubbed along the spine in the later stages of hooping-cough. One ounce of rectified oil of amber, with half an ounce of tincture of opium, forms a good embrocation in tic-doloureux ; its disagreeable odour is an obstacle to its employment when the face is the seat of the disease; but it proves a most valuable application when the limbs begin to lose their tone and swell in advanced life. It is extremely efficacious against the cramps of the Ihnbs.in Asiatic cholera, but which may be prevented by pressing the foot against a board or other firm body at the foot of the bed, when the patient feels cramp comiug ou.