Aloes
Description
The juice from the Aloe genus of plants characterized by their spiny leaves. Examples of these lily-like plants include: Aloe vera (True aloe or common aloe); Aloe vulgaris (Barbados aloes), A.sinuta, A. socotrina (Socotrine or Bombay aloes), and A. capensis (Cape aloes). Heating the juice produces a thick, dark brown resin that has been used as a varnish to protect gilding. Aloes has also been heated to dryness to produce a brown residue that is ground to form a pigment. It contains barbaloin and small amounts of the C-glycoside of aloe-emodin (White 1986). Aloes was also used as a dye forming a yellowish brown color on wool or pale gray on cotton with an alumina mordant.
Synonyms and Related Terms
socotrine aloes; hepatic aloes; Caballine aloes; Aloe vera (True aloe or common aloe); Aloe vulgaris (Barbados aloes); A.sinuta; A. socotrina (Socotrine or Bombay aloes); A. capensis (Cape aloes).
Other Properties
- Soluble in hot water, alcohol, ether and essential oils.
- Aloe has a bitter flavor and strong odor.
- Refractive Index = 1.619
Resources and Citations
- R.White "Brown and Black Organic Glazes, Pigments and Paints" National Gallery Technical Bulletin, 10:58-71, 1986.
- Wikipedia: Aloe: species list at http://en.wikipedia.org/wiki/List_of_Aloe_species
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 671
- Encyclopedia Britannica, http://www.britannica.com Comment: Aloe" [Accessed May 8, 2003].
- Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
- F. Crace-Calvert, Dyeing and Calico Printing, Palmer & Howe, London, 1876 Comment: p.278
- CRC Handbook of Chemistry and Physics, Robert Weast (ed.), CRC Press, Boca Raton, Florida, v. 61, 1980 Comment: ref. index=1.619