ASTRINGENT DYES.

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“ usual mordant.” Cork-cutters 1 waste, digested with nitric acid, yields aprimrose-yellow colouring matter,—probably an impure or modified picricacid,—which was at one time used for dyeing yellow waistcoatings.

Dyer’s Woodruf (Asperula tinctoria) is cultivated and used to a smallextent in Dalmatia as a substitute for madder.

Gammam.—A dye-ware from Tunis. Samples were sent to the Exhibitionof 1851, but it has not been introduced into the market.

Golden Rod (Solidago Canadensis) is stated to produce good yellowshades,—similar to those yielded by weld,—both upon animal and vegetabletissues. It is not met with in the English market. Its mordant is alum.

Green Ebony.—A wood sold under this name has sometimes been used asa yellow dye, especially in compound colours, such as greens.

Heath.—In former times common heath was used as a dye-ware, and gavea yellow colour upon woollen goods. It is now quite superseded by richerwoods and barks.

Hellebore (Hellcborus trifolius). —The Canadian three-leaved hellebore isused by the native Indians for dyeing skins and wool a yellow.

Hemlock.—The bark of the “hemlock spruce” (Abies Americana) containstannin, and has been experimentally used for dyeing. The results were notencouraging, as the blacks and other sad colours produced have an unpleasantrusty-red, or, as it is technically called, “ foxy ” reflection.

Hiccory.—The bark and nuts of the “American hiccory, or walnut tree”were claimed by Dr. Bancroft, in his patent of October 23, 1775, as capableof producing yellow and green colours with a mordant of alum and verdigris.The material never came into extended use.

Holly.—Ilixanthine, a principle obtained from the common holly, is insolublein cold water, soluble in hot water and alcohol, with a yellow colour ; insolublein ether, but soluble in hot concentrated hydrochloric acid. With alum itdyes a yellow, and with ferric chlorides a green.

Hollyhock.—The common garden hollyhock is said to contain, in its stem,a blue colouring matter not unlike indigo. This colour has never beenobtained upon a manufacturing scale, and its properties are still a matter ofdispute.

Horse-chestnut.—The cotyledons of the horse-chestnut fruits contain,according to Rochleder, argyrescin, a yellow colouring matter.

Horse-radish.—This plant contains a yellow colouring principle, notin use.

Khail-cedra, obtained from Khaya Senegalcnsis , yields red or yellowcolours. (Caventon, “Journ. Pharm.,” xvi., 355, and xxxiii., 123).

Lamium album ( The Dead Nettle).—- This plant yields yellow and greencolours of no value.

Lamium purpureum produces, with preparations of tin, a reddish-grey,and with iron liquor a greenish colour.

Lawsonia inermis, the henna of the Arabs, is used in the East for staininghorse-hair, leather, and human finger-nails a reddish-purple. Its use has beenpatented in France for dyeing blacks.

Lithospermum arvense.—The root-bark yields a red colour resemblingthat obtained from alkanet root. It forms, however, a blue solution in ether,whilst alkanet gives with the same solvent a red.