Lead(II) acetate

Lead(II) acetate is a chemical compound, a white crystalline substance with a sweetish taste. It is made by treating litharge (lead(II) oxide, PbO) with acetic acid. Like other lead compounds, it is very toxic. Lead acetate is soluble in water and glycerin. With water it forms the trihydrate, Pb(CH₃COO)₂·3H₂O, a colorless or white efflorescent monoclinic crystalline substance. Lead(II) acetate is also known as lead acetate, lead diacetate, plumbous acetate, sugar of lead, lead sugar, salt of Saturn, and Goulard's powder (after Thomas Goulard).

The substance is used as a reagent to make other lead compounds and as a fixative for some dyes. In low concentrations, it is the principal active ingredient in progressive types of hair coloring dyes. Lead(II) acetate is also used as a mordant in textile printing and dyeing, as a drier in paints and varnishes, and in preparing other lead compounds.

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Historical use

Lead acetate has a sweet taste, which has led to its use as a sugar substitute throughout history. The ancient Romans, who had few sweeteners besides honey, would boil must (grape juice) in lead pots to produce a reduced sugar syrup called defrutum, concentrated again into sapa. This syrup was used to sweeten wine, and to sweeten and preserve fruit. It is possible that lead acetate or other lead compounds leaching into the syrup might have caused lead poisoning in anyone consuming it.^[1]

Pope Clement II died in October 1047. A recent toxicologic examination^{[citation needed]} of his remains confirmed centuries old rumors that the Pope had been poisoned with lead sugar. It is, however, not clear whether he was assassinated or not, as lead sugar in those times was often used as a cure for venereal diseases.

In 1787 Albert Christoph Dies swallowed, by accident, three-quarters of an ounce of lead acetate. His recovery from this poison was slow and incomplete. He lived with illnesses until his death in 1822.

Mary Seacole applied it among other remedies against an epidemic of cholera in Panama^[2][3].

Sugar of lead has also been used to treat poison ivy.

Lead acetate is no longer used as a sweetener in most of the world because of its recognized toxicity.

Other uses

Lead acetate, as well as white lead, have been used in cosmetics throughout history, though this practice has ceased in Western countries.^[4] It is still used in men's hair coloring products^[5] like Grecian Formula.

Lead acetate paper is used to detect the poisonous gas hydrogen sulphide. The gas reacts with lead(II) acetate on the moistened test paper to form a grey precipitate of lead(II) sulphide.

Biological hazards

Lead(II) acetate, among other lead salts, has been reported to cross the placenta and to the embryo leading to fetal mortality. Lead salts also have teratogenic effect in some animal species.

References

1. ^ [1]
2. ^ Mary Seacole: Wonderful Adventures of Mrs. Seacole in Many Lands, Chapter IV, (1990 Oxford University Press reprint) ISBN 0-19-506672-3; (2005 Penguin 20th Century Classics reprint, ed. Sarah Salih) ISBN 0-14-043902-1
3. ^ Jane Robinson: Mary Seacole: The Charismatic Black Nurse who became a heroine of the Crimea, p.53. Constable 2004 (p/b. ISBN 1-84119-677-0)
4. ^ Gunn, Fenja. (1973). The Artificial Face: A History of Cosmetics. — as cited in Leisure Activities of an 18th Century Lady
5. ^ Lead Based Hair Products: Too Hazardous for Household Use - Results, Howard W. Mielke, PhD, Myiesha D. Taylor, Chris R. Gonzales, M. Kelley Smith, Pamela V. Daniels, and Ayanna V.Buckner. Journal of American Pharmaceutical Association (NS37, Jan/Feb 1997:85-89).