Description: Natural Order, Coniferae. Pinus Canadensis of many authors. Generic characters the same as in the balsamea. A. CANADENSIS: Leaves linear, flat, obtuse, about half an inch long, silvery beneath. Cones oval, three-fourths of an inch long, terminal, pendulous, of few scales; bracts evanescent, scales persistent, sterile catkins scattered. This tree is common in the moist lands of the Middle and Eastern States, and Canada. It frequently attains a height of sixty and eighty feet. The coarse-grained timber of hemlock is employed in some of the rougher branches of carpentry. The bark is employed largely in tanning. The bark yields a heavy, nearly black gum-resin, called Hemlock Gum, Hemlock Pitch, and Canada Pitch. Moderate quantities of it exude from the tree spontaneously; but it is usually obtained by gathering the bark of the large trees in the fall or winter, breaking it up, and boiling it in an abundance of water. The gum-resin rises to the surface, and may be taken off when the water cools. By boiling this product in a second water, it is much improved by the complete separation of extraneous matter.
Properties and Uses: I. The inner bark is among the most positive of the drying astringents, and is seldom used internally. Dr. S. Thomson, in his earlier practice, employed a considerable portion of it in his Composition Powder; but finally abandoned it, on account of its extremely drying nature. A strong decoction of it may be employed to advantage as a wash in fungous sores, in foul and phagedaenic ulcers, and in the indolent ulcers of an opened bubo. In combination with a moderate portion of the capsicum or xanthoxylum, it may be used as a wash in bad aphthous sores; or the powders may be applied directly to indolent or phagedaenic chancres. It has been used in pile ointments, to arrest hemorrhage; and is good in all hemorrhages, when pure astringents will answer the purpose. Combined with zingiber and capsicum, the infusion acts promptly and powerfully in flooding and in bleeding from the lungs.
II. The leaves are relaxing and stimulating, rather prompt in their action, and expend their influence upon the skin, kidneys, and uterus. A free use of the warm decoction induces full perspiration, and may be used in recent colds, suddenly suppressed menstruation, and recent rheumatism. It has been used in family practice in deficient lochia; and would be good when there was no feverishness, but would not answer when there was extreme depression. A strong cold infusion has been commended for pain in the back with turbid urine; in leucorrhea, and in mild cases of what might be termed sympathetic prolapsus. Some have asserted that these leaves are valuable in gravel, but the idea lacks confirmation. The warm infusion has been found useful in wind colic, and in the vomiting of cholera morbus and pregnancy. Vapor arising from water containing the leaves, is an excellent local application in sprains, stiff joints, and rheumatism; and a general vapor-bath of the same is a powerful relaxing application in recent colds, and in rheumatism. It is a popular practice to have the patient sit over the vapor from these leaves in acute dysentery and suppressed menstruation. A fomentation of the leaves is good in the swelled breasts and testes following translation of the mumps; and will probably be found useful in other indurated swellings, as scrofula. It is not proper to use them internally during active pneumonia, peritonitis, etc.
III. An oil is obtained from the leaves by distillation. It is a pungent stimulant and relaxant. Combined with alcohol, it is an excellent rubefacient. Internally, it is warming to the stomach, and too excessively irritating to the uterus. The essence has been employed in wind colic.
IV. The gum (more properly the gum-resin) is usually softened with sweet oil, combined with resinous substances, and used as a plaster for weakness in the loins. It is slowly stimulating, and is probably among the best of the articles thus employed. Internally, in doses of ten or more grains, three times a day, it is said to be a slow stimulant to the kidneys and uterus.
Pharmaceutical Preparations: The oil enters into the Stimulating Liniment, and into essences; the gum into plasters.
The Physiomedical Dispensatory, 1869, was written by William Cook, M.D.
It was scanned by Paul Bergner at http://medherb.com