the Week of Proper 28 / Ordinary 33
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Bible Encyclopedias
Pyrogallol
1911 Encyclopedia Britannica
or Pyrogallic Acid, a trioxybenzene, C 6 H 3 (OH) 3 (1: 2: 3), prepared by Scheele in 1786 by heating gallic acid, C 6 H 2 (OH) 3 CO 2 H. It is also obtained by heating para-chlorphenoldisulphonic acid with potassium hydroxide.
It forms white plates, melting at 132°, readily soluble in water, and subliming without decomposition. It is an energetic reducing agent, a property utilized in its application in gas analysis to absorb oxygen, and in photography as a developer. The aqueous solution is turned bluish black by ferrous sulphate containing a ferric salt. It does not combine with hydroxylamine, as does the isomeric phloroglucin which yields a trioxime(see Polymethy1.Enes).' Pyrogallol dimethyl ether is found in beechwood tar. Pyrogallol has antiseptic properties and is employed medicinally in the treatment of psoriasis. Eugallol, or monacetyl pyrogallol and lenigallol, or triacetyl pyrogallol, are also used.
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Chisholm, Hugh, General Editor. Entry for 'Pyrogallol'. 1911 Encyclopedia Britanica. https://www.studylight.org/​encyclopedias/​eng/​bri/​p/pyrogallol.html. 1910.