Burgundy pitch is a resinous exudation obtained from the stem of Picea excelsa, Link. (N.O. Coniferae), and purified by melting and straining. It is obtained chiefly from Finland and the Black Forest. Incisions are made in the bark, and the exuding oleoresin is scraped out of the holes in which it has solidified, after which it is melted under water, and strained. It is an opaque, hard, brittle, reddish or yellowish-brown substance, which gradually assumes the form of
the vessel in which it is kept. It breaks with a clean conchoidal fracture. The odour is aromatic; taste, sweet and aromatic. A factitious Burgundy pitch is prepared by melting together common pitch, resin, and turpentine, and agitating the mixture with water Its odour differs from that of the genuine substance, and it does not form a clear solution with glacial acetic acid. Burgundy pitch should, be soluble in twice its weight of glacial acetic acid, and readily soluble in alcohol.
Constituents.—The chief constituents of the pitch are resin and a little volatile oil; the resin appears to consist of α- and β-piceapimarolic acids with small quantities of picea-pimarinic and piceapimaric acids, and a resene (juro-resene).
Action and Uses.—Burgundy pitch is a mild counter-irritant, and is employed in the preparation of plasters (as Emplastrum Picis) for application to the loins in lumbago, to the chest in pulmonary affections, and to painful rheumatic joints.
- Emplastrum Picis, B.P.—PITCH PLASTER. Syn.—Poor Man's Plaster.
- Burgundy pitch, 52; frankincense, 26; resin, 9; yellow beeswax, 9; olive oil, 4; distilled water, 4. Melt together the frankincense, beeswax, pitch, and resin; add the oil and water, and, with constant stirring, evaporate to a suitable consistence. Pitch plaster is a mild counter-irritant. It is applied to the chest in chronic bronchitis, to the joints in chronic rheumatism, and to the loins in lumbago.