ARNOT'TO, ARNATTO, ANNOTTA, ANNATTO, or ROT:C01:1, also known on the continent of Europe by the name of ORLEAN, is a red coloring matter, which is obtained in South America and the West Indies from the reddish pulp surrounding the seeds of the Arnotto tree (bixa orellana) by washing, maceration, fermentation, and subsequent evaporation. It appears in commerce in cakes or balls of 2 to 4 lbs. weight, wrapped up in leaves, externally brown, internally of a pale blood-red or yellowish-red color, and which have a peculiar animal smell and an astringent taste. Pure A. seldom appears in the market. It is obtained by the mere rubbing off and drying of the red pulpy pellicle which covers the seed ; but that which is thus obtained is very pure, and occurs in small round or angular lozenges. The Indians rub this coloring matter into the skin of their whole body, thus intending both to adorn themselves, and to obtain protection against the bites of mosquitoes. Amongst us, A. is used in medicine for coloring plasters, ointments, etc.; and to a considerable extent by fanners for giving a rich color to cheese. It is also used in dyeing, although it does not produce a durable color. It is employed to impart an orange tint to simple yellows. It is an ingredient in some varnishes. It dis
solves in alkalies, producing a brown solution, from which it is precipitated yellow by acids. It imparts little color to water, but dissolves in alcohol ; alum and sugar of lead throw down a brick-red precipitate from the alcoholic solution. In South America, A. is very extensively mixed with chocolate, not only for the sake of the color, but also for the improvement of the flavor.—The genus Urn belongs to the natural order flacour tiacem (q.v.), and is distinguished by complete flowers with simple stigma, a hispid calyx of five sepals, and a two-valved capsule. The A. shrub is a native of tropical America, but has been introduced into other warm countries. It grows to the height of 7 or 8 ft., and has heart-shaped pointed leaves, and large flowers of a peach-blossom color, which grow in loose clusters at the extremities of the branches. The capsules are oblong, and contain 30 to 40 seeds enveloped in red pulp (the A.). The seeds are said to be cordial, astringent, and febrifugal. The roots are used in broth. They have the properties of A. in an inferior degree.