​SORREL, the Common Wood, Sour Trefoil, or Cuckow-Bread. Oxalis Acetosella, L. another native perennial, which abounds in woods, shady hedges, and on heaths: it flowers in the month of April.—This vegetable is eaten by goats, hogs, and sheep; but is not relished by cows, and is refused by horses. Its purple leaves yield, on expression, a gratefully acid juice, which has been beneficially used in scorbutic eruptions: and, if such juice be properly clarified, evaporated, and deposited in a cool place, it will produce a considerable quantity of acid crystals, which may be employed for removing iron-moulds from linen-cloth; and which are sold under the name of Essential Salt of Lemons.—An infusion of the leaves makes a palatable diet-drink in ardent fevers; and, on being boiled in milk, they form an agreeable whey. They have also been successfully applied to scrophulous ulcers, when rolled in a cabbage leaf, and digested in warm ashes, till they were reduced to a pulp.—But the most easy and efficacious way of preserving these leaves, is that of converting them into a kind of conserve, with the addition of double their weight of sugar; in which form, they are an excellent substitute for lemons, and may be given with advantage in all putrid and other fevers, where antiseptics are indicated.