This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Oil of Amber (Oleum Succini, U. S.), in its impure commercial form, is obtained from amber by subjecting it, mixed with sand, to dry distillation. A sour liquid comes over, on the surface of which a very dark-coloured oil floats, which is removed, and constitutes the crude oil of commerce. The rectified oil is obtained from this by distillation with water.
Rectified oil of amber thus obtained is of a light yellowish-brown or amber colour, a strong, peculiar, disagreeable odour, and a hot acrid taste. It is insoluble in water, but is dissolved by alcohol and the fixed oils. Exposed to the air, it absorbs oxygen, and gradually darkens and thickens, until at last it becomes black and solid. It consists, when pure, of carbon and hydrogen, but contains oxygen as found in the shops.
Oil of amber is locally and generally stimulant, exciting both the circulation and the nervous system, and sometimes promoting the secretions. It has been employed in most of the diseases to which this class of medicines are considered applicable; as tetanus, epilepsy, hysteria, hooping-cough, and the convulsive affections of children. It has also been given in amenorrhoea. The dose is from five to fifteen drops, which may be most agreeably given in emulsion, made with gum arabic, sugar, and one of the aromatic waters.
The oil has been used locally, as an antispasmodic liniment, rubbed on the skin along the whole length of the spine, in hooping-cough, and infantile convulsions. It has also been employed in chronic rheumatism and palsy, as a rubefacient. In the convulsions of children, connected with intestinal spasm, the late Dr. Joseph Parrish was in the habit of using a liniment composed of equal parts of this oil and laudanum, mixed with three or four parts of olive oil and brandy. It was rubbed freely along the spine. It is said to be a very efficient remedy for piles, applied locally to the tumours. (Prof. Procter, Am. Journ. of Pharm., May, 1866, p. 217).