Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 4, 1802).djvu/296

266&#93; 266] VER tation ; when they speedily become acid, and corrode the copper: after the plates have stood in such situa- tion for a sufficient time, they are moistened with water, and exposed to the air ; the verdigrease being succesiiivcly scraped olF, as it col- lefts on the surface. In this state, the acetite is called fresh or moist verdigrease, having the form of paste ; which, after triturating it in proper trouglis, is put in bags, and dried in the sun. — It pays, on importation, a duty of 34d, per lb. Crystals of l^erdigrease are pre- pared by saturating vinegar with the common acetite of copper, and leaving the solution to clarify ; after which it is poured into a kettle, where it is evaporated till a pellicle appear on the surface : when cool, the vessel is furnished with small sticks, on which the crj'stals gra- dually settle : — they are subjed in the Custom-house to the charge of Is. ifd. per lb. Verdigrease is chiefly consumed for striking a black colour, when combined with a deco6tion of log- wood ; but, as it is apt to corrcxie the texture of the cloth, the So- ciety for the Encouragement of Arts, &c. in 1783, conferred their silver medal and teft guineas on Air. Clegg, for his discovery of a substitute for verdigrease, in dyeing tlack. He direfts equal parts, by weight, of vitriol of copper and of pot-ash, or other strong alkaline salt, to be separately dissolved : the solutions are thei^ to be gradually mixed ; and, if the vitriol be satu- rated, the water on the iurface will become transparent, on adding a few drops of the alkaline solution : in the contrary case, a blue colour will be produced ; so that more ?shes should be added, till a com- plete satnratiijn be «-JKf<Iit«"(l. Mr, VER C. observes, that these proportions of vitriol and alkaline salt, will he equivalent to a similar quantity of verdigrease; and, on being com- bined with decoctions of logwood, they impart a tine black dye, which is not injurious to the texture of cloth, ha»s, or any other article that may be tinged of such colour, ■ Verdigrease is, in surgical cases, sometimes applied externally} it operates as a mild detergent in cleansing foul ulcers, or other open wounds. — On account of its viru- lent proj)erties, however, it ought not to be used as a medicine, with- out professional advice; and, in case any portion of this poisonous substance be accidentally swallow- ed, we refer to the remedies al- ready pointed out, vol. i. pp. 74- VERDITER, a preparation of copper, which is occasionally used by painters as a Hue, but more ge- nerally,in combination with a yellow pigment, for a green colour. It is obtained in the following manner : —Let pure copper be dissolved in aqua-fortis ; pulverized quick-lime be added to the solution ; and the whole be well stirred. When the precipitate has subsided, it must be repeatedly washed in pure water ; levigated while moist j and from 5 to 10 parts of quick-lime be in- corporated with 100 parts of such prfcipitate : after which it is tit for Use. — See also vol. ii p. 3/. 'E1UUICE, an acid liquor pre- pared from grapes or apples, that are unfit to be converted into wine or cyder. It is also made from crabs ; which, after being laid in a heap .o sweat, are next stamped or ground in a mill : the pulp is put into bags, and submitted to the ac- tion of a press, in order to obtain all liic juice ; which is then poured inta