Manna
"a small, round thing, as small as the hoar frost," which lay on the face of the wilderness every morning except on the Sabbath (Exod. xvi: 14, 26, 27), sent by Jehovah as bread rained from heaven (ver. 4, 5), and continued during the whole 40 years of the Israelite wanderings in the wilderness (ver. 35). It melted when the sun became hot (ver. 21), and if left till next day bred worms and stank (ver. 20). An omer of it was preserved to show to future generations the nature of the food divinely provided in the desert.
Attempts have been made to identify it with some of the other substances now named manna.
In botany, a concrete discharge from the bark of Fraxinus rotundifolia and some other species of the genus, including in the S. of Europe the common ash, F. excelsior. The sweetness is due to the presence, not of sugar, but of mannite. Eucalyptus mannifera, an Australian tree, exudes a substance like manna, but less nauseous. Manna of Briançon is an exudation from the common larch. Manna of Mount Sinai is an exudation produced by the puncture of an insect, Coccus manniparus on Tamarix mannifera.
In chemistry, a saccharine juice which exudes from certain species of ash, chiefly Fraxinus ornus, found growing in the S. of Europe and in Asia Minor. It has an odor resembling that of honey, and tastes nauseously sweet, with a slight acridity. It is soluble in water and alcohol, and its aqueous solution readily undergoes fermentation, yielding a liquid with a peculiar odor and containing butyric acid.