A New Supplement...: Lake

A New Supplement to the latest Pharmacopoeias of London, Edinburgh, Dublin, and Paris, Forming A Complete Dispendatory, Conspectus, and Dictionary of Medical Chemistry, Giving All the Old and New Names, Including the New French and American Medicines, and Poisons; with Symptoms, Treatment, and Tests; as Well As Herbs, Drugs, Compounds, Veterinary Drugs, With the Pharmacopoia of the Vetenary College, Nostrums, Patent Medicines, Perfumery, Paints, Varnishes, And similar articles kept in the Shops; With Their Compositions, Imitations, Adulterations, And Medicinal Uses, Being a General Book of Formulæ and Recipes For Daily Reference in the Laboratory and at the Counter.
Fourth edition, corrected, improved, and very much enlarged.
By James Rennie, M. A., Editor of the Quarterly Journal of Foreign Medicine; the Pharmacopeia Universalis; Author of a Conspectus of Prescriptions in Medicine, Surgery, and Midwifery; the Pharmacopeia Imperialis, &c. &c.
London: Baldwin and Cradock. 1837.
London: Thomas Curson Hansard, Paternoster Row.

LAKE, a word apparently derived from Lac, and used to designate various kinds of transparent red and other colours used in painting. The chief bases of lakes are cochineal, madder, Brazil wood, quercitron bark, and lac.

Carminated Lake. Boil one part of madder in twelve or fifteen pints of water till it is reduced to two pints; strain through a strong linen cloth by pressure, and add four ounces of alum. Mix this to a consistence with very fine clay, or Spanish white, put it on a filter, wash it to remove the alum, and dry it.

Common Lake. Boil four ounces of Brazil-wood sawdust in fifteen pints of pure water, till reduced to two pints, and add 3iv or 3v of alum. Strain by pressure, and add 3iv of carbonate of soda cautiously, which will precipitate the lake that is to be washed and dried in small globules, as before.

Florence or Florentine Lake is prepared by boiling the sediment remaining after making carmine, in about four quarts of water, or of the carmine water, and precipitating with solution of bichloride of tin, which precipitate is to be carefully washed. Then take 3ij of fresh cochineal (or for cheapness 1bj of Brazil-wood), and 3j of crystals of tartar, boiled in a sufficient quantity of water, pour off clear, precipitate as before with solution of bichloride of in, and wash. At the same time dissolve 1bij of alum in water, precipitate with a solution of potass, and wash the white earth of alum thus procured with boiling water. Mix these precipitates while liquid, and dry them on a filter.

Kermes Lake is prepared like red lake, from kermes.

Lac Lake. Boil stick lac in water, fukter tge decoction, and evaporate the clear liquor to dryness over a gentle fire. The colour spearates from the gum, which is as good as before for making sealing-wax.

Liquid Madder Lake, or Liquid Rubiate, a concentrated tincture of madder, of a transparent rose colour. It may be used as a fine red ink for marking, as it bears washing. (FIELD.)

Madder Lake, or Rubric or Fields' Lake. Tie up in a bag of fine strong calico  3ij of Dutch madder, put it in a stone mortar with a pint of clear soft water, and beat it well without tearing the bag. Pour off the coloured water, add more, and repeat the process till the water is no longer coloured. Heat till near boiling all the coloured water in an earthen or silver vessel, pour into a basin, add 3j of alum dissolved in a pint of boiling water, stir, and add 3jss of solution of carbonate of potass. Wash and dry the precipitate as before.

Red Lake. Take one part of cochineal, and two by weight of spirit of wine, and as much distilled water; infuse for some days in a gentle heat and filter. To the filtered liquor add a few drops of solution of bichloride of tin; an continue to do this from time to time till no precipitate falls. Wash this precipitate with distilled water and dry it. It is thus also that carmine may be made.

Yellow Lake. There are several different pigments thus denominated, usually in the form of drops, very brght and transparent; but are bad driers, and soon fade by exposure to light. Quercitron lake is the best of these, and is a darks substance with a glossy fracture, used with gamboge and varnish, but spoiled by metallic colours. (FIELD.) SEE OIL COLOURS.

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