The bark and prepared resinous exudate of Tsuga canadensis, Carriére (Abies canadensis, Michaux; Pinus canadensis, Linné). (Nat. Ord. Coniferae.) A well known and handsome evergreen tree of the forests of Northern United States and Canada.
Common Names: Hemlock, Hemlock Spruce.
Principal Constituents.—The oleoresin Canada pitch, and a volatile oil known as Oil of Hemlock or Oil of Spruce; that from the leaves is known as Pine-needle Oil, and contains pinene, bornyl acetate, and cadinene; the bark contains a large amount of tannic acid.
Preparations.—1. Specific Medicine Pinus. Dose, 5 to 60 drops.
2. Oil of Hemlock. Dose, 1 to 5 drops.
Specific Indications.—General asthenia, with feeble digestion, vascular weakness, and pale and relaxed mucosa; broncho-pulmonic irritation, with profuse secretions; coughs and colds; pyrosis with gastric irritation, vomiting, and diarrhoea. Contraindicated in inflammations.
Therapy.—External. A strong decoction of the bark is a satisfactory astringent for the checking of leucorrhoea and a good local application of this type for aphthous and other oral ulcerations, gangrenous ulcers, prolapsus ani and prolapsus uteri. The specific medicine on cotton. may be applied to the cervix uteri to heal abrasions and control discharge. The oil may be used as an embrocation for painful and swollen parts, and by spray in nose and throat disorders attended by mild catarrhal symptoms. It enters into many proprietary and semi-proprietary preparations for the treatment of coryza, congested turbinates, and ulcerations of the nasal fossae and throat. The oil dropped upon boiling water is a time-honored inhalation for croup. It has also been used to advantage in some forms of eczema, particularly the weeping type.
Internal. Pinus Canadensis, the name under which most of the alcoholic preparations pass, is mildly stimulant, antiseptic, and useful where an astringent remedy is desired in conditions of relaxation, with pallid mucosa. In small doses, the specific medicine may be employed in gastric irritation and in that of the urinary organs, in both of which there is an excess of mucous secretion. As a remedy for passive hemorrhages it has little to commend it, though it is not wholly without effect, acting much like but with less power than the oil of erigeron and similar preparations. Both the specific medicine and the oil may be incorporated into cough medicines, to be used where there is excessive secretion of mucus and the cough is largely precipitated by a feeble and relaxed state of the uvula and fauces.
The Eclectic Materia Medica, Pharmacology and Therapeutics, 1922, was written by Harvey Wickes Felter, M.D.