MACKEREL. The Scomber Scombrus (Linn.), a well-known spiny-finned sea-fish, much esteemed at certain seasons for the table. Though nutritious, it is very apt to disagree with delicate stomachs, and occasionally induces symptoms resembling those of poisoning.
MAD′DER. Syn. Rubia, Rubiæ radix, L. The root of Rubia tinctorum (Linn.), or dyer’s madder. The best madder has the size of a common goose-quill, a reddish appearance, and a strong odour. As soon as the roots are taken from the ground they are picked and dried; and before use they are ground in a mill. Levant, Turkey, and Smyrna madder is imported whole; French, Dutch, and Zealand madder, ground. The finest quality of ground madder is called ‘crop’ or ‘grappe,’ ‘ombro’ and ‘gamene’ are inferior sorts, and ‘mull’ the worst.
Madder contains several distinct principles as—madder red, or alizarin;—madder purple, or purpurin;—madder orange, or rubiacin; madder yellow, or xanthin, &c. The first of these (noticed below) is by far the most important.
Pur. Madder is frequently adulterated with logwood, Brazil wood, and other dye-stuffs of inferior value; and also, not unfrequently, with brickdust, red ochre clay, sand, mahogany sawdust, bran, &c. These admixtures may be detected as follows:—
1. When dried at 212° Fahr., and then incinerated, not more than 10% to 12% of ash should be left.
2. It should not lose more than 50% to 56% by exhaustion with cold water.
3. When assayed for alizarin (see below), the quantity of this substance obtained should be equal to that from a sample of the same kind of madder which is known to be pure, and which has been treated in precisely the same manner. The operation may be conducted as follows:—500 gr. of the sample are weighed, and, after being dried by the heat of boiling water or steam, are gradually added to an equal weight of concentrated sulphuric acid, contained in a glass vessel, and stirred with a glass rod; after a few hours the charred mass is washed with cold water, collected on a filter, and dried by the heat of boiling water; the carbonised mass (‘garacine’) is next powdered, and treated with successive portions of rectified spirit, to which a little ether has been added, at first in the cold, and afterwards with heat, until the liquid is no longer coloured by it, when the mixed tincture is filtered, and evaporated (distilled) to dryness; the weight of
the residuum, divided by 5, gives the percentage of red colouring matter present. Or,—The dried carbonized matter is exhausted by boiling it in a solution of 1 part of alum in 5 or 6 parts of water, and the decoction, after being filtered whilst in the boiling state, is treated with sulphuric acid as long as a precipitate falls, which is washed, dried, and weighed as before.
Uses, &c. Madder has been given in jaundice and rickets, and as an emmenagogue.—Dose, 1⁄2 dr. to 2 dr., twice or thrice a day. It is principally employed as a dye-stuff. See Red dyes, Ivory, Purpurin, &c., also below.
MADDER RED. Syn. Alizarin. C14H8O4. 2Aq. The red colouring principle of madder, first obtained in a separate form by Robiquet.