TORMENTIL, Tormcntilla otReinalis (Smith), credo (Linn.), a small perennial plant, growing in the whole of Europe and the north of Aaia, in forests, bogs, and heaths. [PoTENTILLA.] The root, or rather the rhizome, is officinal. As the plant flowers in June and July, the best time to collect the rhizomata is in April and May. Those gathered in autumn, while they remain moist, are phosphorescent. The roots of the Tormentilla (Potentilla) reptans (Linn.), of the Potentilla Com marum, those of the common strawberry, of the Geum urbanum, and also of the Polygonura bistorta, are frequently confounded with those of the true tormentil—errors of no great importance as far as their medical employment is concerned, as they possess properties similar in kind, but inferior in degree. In Italy the root of the Geranium 'striatum is substituted for it.
The rhizomata of the genuine plant are large in proportion to the branches they bear. They lie obliquely in the earth; old ones are knotty or resemble knobs, from 14 to 2 inches thick ; younger ones are cylindrical, irregularly branched, the branches 1 to 2 inches long, and from one-fourth to one-half inch thick, curved and twisted. The epidermis and liber are very thin, but firm. The central part presents two or more concentric circles. The colour of the interior, when fresh, is a rose-red or fleshy colour; but when dried, it inclines more to a reddish or brownish yellow ; in very old specimens it becomes white. It can be easily powdered : the powder is of a bright brownish red. The rose-odour of the fresh root is lost by drying. Taste purely aud strongly astringent. Specimens which are dark externally, and woody and white within, are to he rejected.
Water distilled from the fresh root has an agreeable rose-like odour. This plant contains more tannin than any other, except catechu and galls. Tormentil is the most powerful of our indigenous astringents, and more easily assimilated than oak-bark or galls. Though improper in active hemorrhages, in passive discharges it is very useful, and may be given with aromatics, or opiates, or chalk, as in the compound powder of chalk. Few medicines are more efficacious for drying up the slimy mucus in which worms nestle in the intestines of children, than the compound powder of chalk. Infusion made with cold water is preferable to the decoction. The extract made in the common way soon spoils. But valuable as this substance is in medicine, it is of still greater utility in the arts and in agriculture. It may be most bene ficially employed to tan leather, both where the oak grows and where it is absent, since one pound and a half of powdered tormentil is equal in strength to seven pounds of tan. It is used in Lapland and the Orkney Isles, both to tan and to dye leather, and in the latter parts to dye worsted yarn. By long boiling the tannin is converted into gum, and in times of scarcity the poor may collect and obtain much nourish ment from the root. But the great service this plant renders in husbandry is its chief merit. Where it grows abundantly in wet pastures, the rot in the sheep is unknown. Where the heather has been burned on the Highland hills, this plant springs up spontaneously with the tender grass. [ANTHELMNNTICS.]