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LOGWOOD (so called from the See also: heart-See also: wood of a leguminous See also: tree, Haematoxylon campechianum, native of Central See also: America, and grown also in the West See also: Indian Islands
.
The tree attains a height not exceeding 40 ft., and is said to be ready for See also: felling when about ten years old
.
The wood, deprived of its bark and the See also: sap-wood, is sent into the market in the See also: form of large blocks and billets
.
It is very hard and dense, and externally has a dark brownish-red colour; but it is less deeply coloured within
.
The best qualities come from Campeachy, but it is obtained there only in small quantity
.
Logwood is used in dyeing (q.v.), in microscopy, in the preparation of ink, and to a small extent in See also: medicine on account of the tannic acid it contains, though it has no See also: special medicinal value, being much inferior to kino and See also: catechu
.
The wood was introduced into See also: Europe as a dyeing substance soon after the See also: discovery of America, but from 1581 to 166a its use in See also: England was prohibited by legislative enactment on account of the inferior dyes which at first were produced by its employment
.
The colouring principle of logwood exists in the See also: timber in the form of a See also: glucoside, from which it is liberated as haematoxylin by See also: fermentation
.
Hacmatoxylin, C16H,406, was isolated by M
.
E
.
See also: Chevreul in 181o
.
It fonns a crystalline See also: hydrate, C,6l-11406+3H20, which is a colourless See also: body very sparingly soluble in cold See also: water, but dissolving freely in hot water and in See also: alcohol
.
By exposure to the air, especially in alkaline solutions, haematoxylin is rapidly oxidized into haematcin, C16H12O6, with the development of aSee also: fine See also: purple colour
.
This re-See also: action of haematoxylin is exceedingly rapid and delicate, rendering that body a laboratory test for alkalis
.
By the action of hydrogen and sulphurous acid, haematcin is easily reduced to haematoxylin
.
It is chemically related to brazilin, found in See also: brazil-wood
.
Haematoxylin and brazilin, and also their oxidation products, haematin and brazilin, have been elucidated by W
.
H
.
Perkin and his pupils (see Jour
.
Chem
.
See also: Soc., 1908, 1909)
.
LOBAR%, a native See also: state of See also: India, in the See also: south-See also: east corner of the See also: Punjab, between See also: Hissar See also: district and See also: Rajputana
.
See also: Area, 222 sq. m.; pop
.
(1901) 15,229; estimated See also: gross revenue, 4800
.
The chief, whose title isSee also: nawab, is a See also: Mahommedan, of Afghan descent
.
The nawab See also: Sir Amir-ud-din-Ahmad Khan, K.C.I.E., who is a member of the See also: viceroy's legislative council, was until 1905 See also: administrator and adviser of the state of Malec Kotla
.
The See also: town of Loharu had a population in tool of 2175
.
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