Turnsol, or Turnesol, a valuable dyeing drug, which is prepared chiefly in the village of Grand-Galargues, near Montpel-lier, from the Croton tinctoriurn, L. in French called Maarelle: this plant produces a round stalk with many leaves, and seldom exceeds nine inches in height. - It is therefore erroneous, when our voluminous contemporaries uniformly assert, on the authority of M. Nis-sole, that Turnsol is obtained from the tops of the Heliotrobium tri-coccum, L and, though it may be true, that such drug is occasionally manufactured from the latter vegetable, yet the genuine article is doubtless the result of the following process.
Toward the latter end of July, or early in August, the flowering tops of the Maurelle, or Litmus-Croton, are expeditiously collected, and bruised : when the dark-green sap is expressed into stone vessels, with the addition of urine. Linen or woollen rags are next dipped into this liquor, and immediately dried in the sun ; after which they are suspended for seven or eight hours, over casks containing stale urine, quick-lime, and alum, till they acquire a blue or dark-violet colour ; and, if necessary, again immersed in the juice, dried, and treated as before. Thus prepared, they are packed, and sold by the French under the name of Tournesols en drapeau. These blue shreds are chiefly employed for tinging wines, cheese, linen, and paper. When infused with distilled water, they afford an excellent test; for, on pouring a little of this solution into any liquor Containing an acid, it will instantly turn red. - Turnsol pays, on importation, a duty of 5s. 2d. per cwt.