Pois., &c. The soluble preparations of gold (chlorides) are violent poisons. The symptoms resemble those occasioned by corrosive sublimate, but are somewhat less violent. Metallic gold in a minute state of division is also capable of producing very unpleasant consequences, and even endangering life. The antidote is iron filings or a solution of sulphate of iron, given conjointly with an emetic.
Uses. The numerous applications of gold in the arts and the daily transactions of life need only be alluded to here. In medicine, gold has been given in the form of powder, in scrofula and syphilis, by Chrestein, Niel, and others, with apparent advantage.—Dose, 1⁄4 gr. to 1 gr., 3 or 4 times a day, in pills, or as a friction on the tongue and gums. An ointment made of 1 gr. of powdered gold and 30 gr. of lard has been applied by Niel to the skin deprived of the epidermis (endermically) in the above diseases.
The more important chemical compounds containing gold, the alloys and commercial forms of the metal, together with certain factitious substances popularly called ‘gold’, are noticed in alphabetical order below:—
Gold, Alloys and Preparations of:—
Gold, Dutch. Mannheim gold, Mosaic g., Or-molu, Pinchbeck, Prince’s metal, Red brass, Similor, Tombac. These names are applied to several varieties of fine gold-coloured brass, differing slightly in tint and in the proportions of copper and zinc. The terms tombac, prince’s metal, similor, and Mannheim gold, are used by some authors to designate alloys consisting of about 85% of copper and 15% of zinc; whereas, according to other authors, prince’s metal and Mannheim gold are synonymous, and are composed of 75% copper and 25% zinc; according to another author, similor consists of about 711⁄2% copper and 281⁄2% zinc, and Mannheim gold of 80% copper and 20% zinc; and, again, according to another author, similor and Mannheim gold are synonymous, and are applied to alloys of copper containing from 10 to 12% zinc and from 6 to 8% tin. Seeing that such inextricable confusion exists in the employment of the terms above mentioned, it is desirable to discard them altogether. At the celebrated works of Hegermühl, near Potsdam, the proportions copper, 11 parts, to zinc, 2 parts, are employed to produce a metal which is afterwards rolled into sheets for the purpose of making Dutch leaf-gold. This alloy has a very rich, deep gold colour. Its malleability is so remarkable that it may be beaten out into leaves not exceeding 1⁄52900 inch in thickness.
Gold, Facti′′tious. Prep. From copper, 16 parts; platinum, 7 parts; zinc, 1 part; fused together. This alloy resembles in colour gold of 16 carats fine, or 2⁄3, and will resist the action of nitric acid, unless very concentrated and boiling.
Gold, Grain. Syn. Aurum granulatum, L. Prep. From cupelled gold, 1 part; silver, 3 parts; melted together, and poured in a small stream into water; the silver being afterwards dissolved out by digestion in boiling nitric acid, and the grains, after being well washed in water, heated to redness in a crucible or cupel. Used to make preparations of gold.
Gold, Jew′eller’s. This term is applied to alloys of gold used for trinkets and inferior articles of jewelry, ranging from 3 or 4 carats fine upwards; or which are too inferior to receive the ‘Hall mark’. The lowest alloy of this class is formed of copper, 16 parts; silver, 1 to 11⁄2 part; gold, 2 to 3 parts; melted together. This is worth only from 8s. 6d. to 9s. 6d. the oz.
It has recently been found that gold of the quality of 12 carats, or less, if alloyed with zinc instead of the proper quantity of silver, presents a colour very nearly equal to that of a metal at least 21⁄2 to 3 carats higher, or of 8s. or 10s. an ounce more value; and the consequence has been that a large quantity of jewellery has been made of gold alloyed in this manner; and the same has been purchased by some shopkeepers, very much to their own loss as well as that of the public; inasmuch as a galvanic action is produced, after a time, upon gold so alloyed, by means of which the metal is split into several pieces, and the articles rendered perfectly useless.
Gold, Leaf. Syn. Gold-leaf. Gold reduced