Manna

Manna, an exudation from the stem of the so called "flowering" ash of southern Europe, Fraxinus Ornus, collected in the dry weather of July and August, in Sicily, from incisions in the stems of trees eight years old and upwards. A hectare (2-1/2 acres) planted with 4,000 to 5,000 trees yields nearly 200 lbs. of manna. It contains 70 to 80 per cent. of mannite, C₆H_8(OH)6, a sugar-like substance crystallising in rhombic prisms. Manna is used as a mild aperient for children. Somewhat similar substances are oak manna, produced on Quercus Vallonia and other oaks in Kurdistan, by the puncture of an insect; Briancon manna, on the leaves of the larch; Alhagi manna, from the leguminous Alhagi camelorum of Afghanistan, Beluchistan, and Persia; tamarisk manna; and Australian manna, from the leaves of Eucalyptus viminalis.