from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An organic compound, C10H7OH, occurring in two isomeric forms, alpha-naphthol and beta-naphthol.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Either of two isomeric phenols derived from naphthalene; they are used in the preparation of dyes and many other compounds
from the GNU version of the Collaborative International Dictionary of English
- n. Any one of a series of hydroxyl derivatives of naphthalene, analogous to phenol. In general they are crystalline substances with a phenol (carbolic) odor.
from The Century Dictionary and Cyclopedia
- n. Any one of the phenols of naphthalene having the formula C10H7OH.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. either of two phenols derived from naphthalene
They are also called naphthol colours from the use of beta-and alpha-naphthol in their production.
Now the diazo compounds are rather unstable bodies, but they have a great affinity for other compounds, such as naphthol, phenylene diamine, phenol, and combine easily with them when brought into contact with them.
In 1869 and 1870 he was assistant to H. Wichelhaus in Berlin, with whom he worked on the nitration of b-naphthol.
It is a remarkable fact that non-condensed methane derivatives of naphthol, _e. g._, b-naphthol-a-methanesulphonic acid, dissolved in water and partly neutralised, are devoid of tanning character when allowed to act upon pelt.
Leather obtained through the action of [Greek: a] - naphthol is, when freshly tanned, pure white and sufficiently soft and firm, but quickly assumes a brown colour on storing; if, however, [Greek: b] - naphthol is employed, a cream-coloured leather results, the colour of which turns only slightly more yellowish even when exposed to the direct rays of the sun.
The condensation product of b-naphthol above referred to precipitates gelatine and aniline hydrochloride and gives a brown coloration with ferric chloride.
From [Greek: a] - and [Greek: b] - naphthol a number of sulphonic acids may easily be prepared; viz., mono -, di -, and trisulphonic acids.
If, on the other hand, a pasty mixture is made of formaldehyde and naphthol, and this is allowed to act upon the pelt, the latter is rapidly converted into leather, but the mixture must be administered very gradually or otherwise the insoluble methylenedinaphthol is formed outside the pelt and hinders any tanning effect.
In the naphthalene series, on the other hand, the ring closes up by, for instance, the condensation of [Greek: b] - naphthol with benzaldehyde or paraldehyde, and yields the following compounds: --
The antiseptic sutures and ligatures should be similarly soaked in beta-naphthol solution during the progress of the operation.
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