Etching Ground. Syn. Etching varnish. Prep. 1. Beeswax, 5 parts; linseed oil, 1 part; melted together.
2. (Callot’s Hard varnish, Florentine v., Florence v.) From linseed oil and mastic, equal parts, melted together.
3. (Callot’s Soft varnish.) From linseed oil, 4 oz.; gum benzoin and white wax, of each 1⁄2 oz.; boil to two thirds.
4. (Lawrence.) White wax, 2 oz.; black pitch and Burgundy pitch, of each 1⁄2 oz.; melt, add by degrees, of powdered asphaltum, 2 oz.; and boil together, until a piece, when thoroughly cold, will break by being bent double 2 or 3 times between the fingers; next pour it into warm water, make it into small balls, and place each of them in a piece of taffety for use.
Obs. The preceding compositions are applied to the surface of the plates, previously made sufficiently warm to melt them easily, their even diffusion being promoted by dabbing them with a wad of cotton. Those that are white are then generally blackened on the surface by skilfully passing them over the smoky flame of one or more candles, by which the marks of the etching point on the bright metal are rendered the more visible.
E′THER. Syn. Oxide of ethyl. Described under Ethyl, Oxide of. Several substances are known under the name of ethers besides the true ethers or salts of ethyl, and are given below.
Ether of Canthar′ides. Syn. Æther cantharidalis, L. Prep. (Œttinger.) From powdered cantharides, 1 part; ether, 2 parts; digested together for 3 or 4 days, and the tincture expressed. Used as a vesicant, &c.
Ether, Chlo′′ric. This name was applied by Dr T. Thomson to the CHLORIDE OF OLEFIANT GAS, or ‘Dutch liquid,’ and afterwards, by Guthrie and Silliman, to CHLOROFORM, which they took for an alcoholic solution of chloride of olefiant gas. It now forms one of the synonyms of chloroform. The medicinal ‘CHLORIC ETHER’ of the shops is a solution of chloroform, 1 part, in rectified spirit 8 parts; of which the dose is 20 or 30 drops in water, as an antispasmodic and anodyne. See Chloroform.
Ether, Chlorinet′ted. Formed by the action of dry chlorine on pure ether. When the action is long continued, a heavy, oily product (BICHLORINETTED ETHER), smelling like fennel, is formed. By the still further action of chlorine, aided by sunlight, a white, crystalline substance (PENTACHLORINETTED ETHER), a compound resembling sesquichloride of carbon, is obtained.
Ether, Cu′′preous. Syn. Tinctura cupri chloridi ætherea, L. Prep. (Van Mons.) Sulphate of copper, 6 parts, and chloride of barium, 5 parts, are triturated together, and the mixture digested in ether, 3 or 4 parts, until all the chloride of copper is dissolved.—Dose, 2 to 5 drops; in epilepsy, &c.