TORMENTILLA, TORMENTIL; a genus of the polygynia order, belonging to the iconandria class of plants. There are two species, the most remarkable of which is the crecta, growing very frequently in barren pastures, moors, and heaths, in Scotland, England, and the neighbouring islands. The roots consist of thick tubercles, an inch or more in diameter, replete with a red juice, of an astringent quality. They are used in most of the Western Isles, and in the Orkneys, for tanning of leather; in which intention they are proved by some late experiments to be superior even to the oak-bark. They are first of all boiled in water, and the leather is afterwards steeped in the liquor. In the islands of Tirey and Col the inhabitants have destroyed so much ground by digging them up, that they have lately been prohibited the use of them. A decoction of these roots in milk is also frequently administered by the inhabitants of the same islands in diarrhoeas and dysenteries, with good success; but perhaps it would be most proper not to give it in dysenteries till the morbid matter be first evacuated. A spirituous extract of the plant stands recommended in the sea-scurvy, to strengthen the gums and fasten the teeth. Linnaeus informs us, that the Laplanders paint their leather of a red colour with the juice of the roots.