Active Ingredients. - Manna is of the consistence of cheese, yellowish-white, faintly odorous, and of a sweetish but sickly flavor. About sixty or eighty per cent. consists of mannite: the other constituents are sugar, of which there are two kinds, one crystallizable, the other not so; a small quantity of gum, some resin, and a little nauseous extractive matter. When pure, it is soluble in three to five parts of cold, and in its own weight of boiling water; and is also soluble in rectified spirit. It melts with heat, and burns with a bluish flame.

Mannite, C3H7O8, may be extracted from the crude manna by means of boiling alcohol, from which, on cooling, it separates in shining, whitish, four-sided, and acicular crystals. It is odorless, sweet, soluble in boiling, less so in cold, alcohol, and is incapable of fermenting with yeast.

1 Comptes Rendus, 1847.

2 Ringer: 7th Ed., 1878, p. 372.

Physiological Action. - Manna is mildly laxative, though it sometimes causes flatulence and griping.

Therapeutic Action. - Manna is well adapted for administration, as a gentle laxative, to infants and young children; also for introduction into purgative mixtures, as an adjuvant.

Preparations And Dose. - Manna, 3 j. - ij.(4. - 8.), for children.