the acetite of copper, much used by painters as a green colour. It is chiefly manufactured at Montpelier; the vines of Languedoc being very convenient for this purpose. See CHEMISTRY, No. 872.

The following process for making verdigris is described by Mr Monet of the Royal Society of Montpelier, and is published among the memoirs of the academy for the years 1750 and 1753.

Vine stalks well dried in the sun are steeped during eight days in strong wine, and afterwards drained. They are then put into earthen pots, and upon them wine is poured. The pots are carefully covered. The wine undergoes the acetic fermentation, which in summer is finished in seven or eight days; but requires a longer time in winter, although this operation is always performed in cellars. When the fermentation is sufficiently advanced, which may be known by observing the inner surface of the lids of the pots, which during the progress of the fermentation is continually wetted by the moisture of the rising vapours, the stalks are then to be taken out of the pots. These stalks are by this method impregnated with all the acid of the wine, and the remaining liquor is but a very weak vinegar. The stalks are to be drained during some time in baskets, and layers of them are to be put into earthen pots with plates of Swedish copper, so disposed that each plate shall rest upon and be covered with layers of stalks. The pots are to be covered with lids; and the copper is thus left exposed to the action of the vinegar, during three or four days, or more, in which time the plates become covered with verdigris. The plates are then to be taken out of the pots, and left in the cellar three or four days; at the end of which time they are to be moistened with water, or with the weak vinegar above mentioned, and left to dry. When this moistening and drying Verditer, of the plates has been twice repeated, the verdigris will be found to have considerably increased in quantity; and it may then be scraped off for sale.

A solution or erosion of copper, and consequently of verdigris, may be prepared by employing ordinary vinegar instead of wine, as is directed in the above process. But it would not have the unctuousness of verdigris, which quality is necessary in painting. Good verdigris must be prepared by means of a vinous acid, or solvent half acid and half spirituous. Accordingly, the success of the operation depends chiefly on the degree of fermentation to which the wine employed has been carried: for this fermentation must not have been so far advanced that no sensibly vinous or spirituous parts remained in the liquor.

Verdigris is employed externally for deterring foul ulcers, and as an emetic. It is rarely or never given internally. Some recommend it indeed in the dose of a grain or two as an emetic, which operates almost as soon as received into the stomach, and which may therefore be of use where poisonous substances have been taken, to procure their immediate rejection. It appears, however, highly imprudent to have recourse on such occasions to a remedy in itself so dangerous and so violent; and more especially as a speedy evacuation may generally be obtained by means of substances which are not only innocent, but at the same time weaken the force of the poison by diluting and obliterating it; as warm water, milk, oils. It is accordingly excluded from the present pharmacopoeia.