See also:

• PYROCATECHIN, or PYROCATECHOL

PYROCATECHIN, or PYROCATECHOL  , ortho-dioxybenzene, See also:

• C6H4
• C6H4(CH213r)2

C6H4(OH)2, first prepared in 1839 by H . Reinsch on distilling catechin (the juice of See also:

• MIMOSA (so named from the movements of the leaves in many species which " mimic " animal sensibility)

Mimosa See also:

• CATECHU

catechu); occurs See also:

• FREE

free in kino and in beechwood See also:

• TAR

tar; its sulphonic See also:

• ACID (from the Lat. root ac-, sharp; acere, to be sour)

acid is See also:

• PRESENT

present in the urine of the See also:

• HORSE (a word common to Teutonic languages in such forms as hors, hros, ros; cf. the Ger. ross)

horse and See also:

• MAN
• MAN, ISLE OF (anc. Mona)

man . It results in the alkaline See also:

• FUSION

fusion of many resins, and may be prepared by fusing ortho-phenolsulphonic acid, o-chlorphenol, o-bromphenol, and o-phenoldisulphonic acid with potash, or, better, by See also:

• HEATING

heating its methyl See also:

• ETHER, (C2H5)2O

ether, guaiacol, C6H4(OH) (OCH3), a constituent of beechwood tar, with hydriodic acid . See also:

• PYROCATECHIN, or PYROCATECHOL

Pyrocatechin crystallizes in See also:

• WHITE
• WHITE, ANDREW DICKSON (1832– )
• WHITE, GILBERT (1720–1793)
• WHITE, HENRY KIRKE (1785-1806)
• WHITE, HUGH LAWSON (1773-1840)
• WHITE, JOSEPH BLANCO (1775-1841)
• WHITE, RICHARD GRANT (1822-1885)
• WHITE, ROBERT (1645-1704)
• WHITE, SIR GEORGE STUART (1835– )
• WHITE, SIR THOMAS (1492-1567)
• WHITE, SIR WILLIAM ARTHUR (1824--1891)
• WHITE, SIR WILLIAM HENRY (1845– )
• WHITE, THOMAS (1628-1698)
• WHITE, THOMAS (c. 1550-1624)

white rhombic prisms, which melt at 104° and See also:

• BOIL

boil at 245°; it is readily soluble in See also:

• WATER

water, See also:

• ALCOHOL

alcohol and ether . Ferric chloride gives a See also:

• GREEN, A
• GREEN, ALEXANDER HENRY (1832—1896)
• GREEN, DUFF (1791—1875)
• GREEN, JOHN RICHARD (1837—1883)
• GREEN, MATTHEW (1696-1737)
• GREEN, THOMAS HILL (1836-1882)
• GREEN, VALENTINE (1739–1813)
• GREEN, WILLIAM HENRY (.1825–1900)

green coloration with the aqueous See also:

• SOLUTION (from Lat. solvere, to loosen, dissolve)

solution, whilst the alkaline solution rapidly changes to a green and finally to a See also:

• BLACK
• BLACK, ADAM (1784-1874)
• BLACK, JEREMIAH SULLIVAN (1810–1883)
• BLACK, WILLIAM (1841-1898)

black See also:

• COLOUR (Lat. color, connected with celare, to hide, the root meaning, therefore, being that of a covering)

colour on exposure to the See also:

• AIR (from an Indo-European root meaning " breathe," " blow ")
• AIR, or ASBEN

air . It reduces See also:

• SILVER

silver solutions in the See also:

• COLD (in O. Eng. cald and ceald, a word coming ultimately from a root cognate with the Lat. gelu, gelidus, and common in the Teutonic languages, which usually have two distinct forms for the substantive and the adjective, cf. Ger. Kolte, kalt, Dutch koude

cold and alkaline See also:

• COPPER (symbol Cu, atomic weight 63.1, H=1, or 63.6, O = 16)

copper on heating . Guaiacol may be obtained directly from beechwood tar, from pyrocatechin by methylation with potash and See also:

• POTASSIUM [symbol K (from kalium), atomic weight 39.114 0=16)]

potassium methyl sulphate at 18o°, or from anisol by nitration, reduction of the ortho-nitroanisol to amino-anisol, which is then diazotized and boiled with water . It melts at 28° and boils at 25o° . It is employed in See also:

• MEDICINE

medicine as an expectorant . The dimethyl ether or veratrol i phosphate (PbCl)Pb4(PO4)3, sometimes occurring in sufficient is also used in medicine . Many other pyrocatechin derivatives have abundance to be See also:

• MINED

mined as an ore of See also:

• LEAD
• LEAD (pronounced iced)

lead. been suggested for therapeutic application . Guaiacol carbonate is known as duotal, the phosphate as phosphatol, the phosphite as guaiaco-phosphal; phosphotal is a mixture of the phosphites of See also:

• CREOSOTE, CREASOTE

creosote phenols .

The valerianic ester of guaiacol is known as geosote, the benzoic as benzosol, the salicylic as guaiacolsalol, while the See also:

• GLYCERIN, GLYCERINE

glycerin ether appears as guaiamar . Pyrocatechin readily condenses to See also:

• FORM (Lat. forma)

form heterocyclic compounds; cyclic See also:

• ESTERS

esters are formed by See also:

• PHOSPHORUS (Gr. 4ws, light, sPEpety, to bear)

phosphorus trichloride and oxychloride, carbonyl chloride, sulphuryl chloride, &c.; whilst ortho-phenylenediamine, o-aminophenol, and o-aminothiophenol give See also:

• PHENAZINE (Azophenylene), C12H5N2

phenazine, phenoxazine and thiodiphenylamine .