REDS. Brazil-wood Lake.—(a) Digest 1 lb. ground Brazil-wood in 4 gal. water for 24 hours, boil 1 hour, aud add 11 lb. alum dissolved in a little water ; mix, decant, strain, add 1 lb. tin solution, again mix well, and filter ; to the clear liquid, cautiously add a solution of carbonate of soda while a precipitate forms, avoiding excess; collect, wash, and dry. The shade will vary according as the precipitate is collected. (b) Add washed and recently precipitated alumina to a strong filtered decoction of Brazil-wood.
Carminated Lake.—(a) The cochineal residue left in making carmine is boiled with repeated portions of water till exhausted ; the liquor is mixed with that decanted off the carmine, and at once filtered ; some recently precipitated alumina is added, and the whole is gently heated, and well agitated for a short time ; as soon as the alumina has absorbed enough colour, the mixture is allowed to settle, the olear portion is decanted, and the lske is collected on a filter, washed, and dried. The decanted liquor, if still coloured, is treated with fresh alumina till exhausted, and thus a lake of second quality is obtained. (b) To the coloured liquor obtained from the carmine and oochineal as just stated, a solution of alum is added, the filtered liquor is precipitated with a solution of carbonate of potash, and the lake is collected and treated as before. The colour is brightened by addition of tin solution.
Carmine.—Boil 1 lb. cochineal and 4 dr. carbonate of potash in 7f gal. water for hour. Remove from the flre, and stir in 8 dr. powdered alum, and allow to settle for 20-30 minutes. Pour the liquid into another vessel, and mix in a strained solution of 1 dr. isinglass in 1 pint water ; when a skin has formed upon the surface, remove from the fire, stir rapidly, and allow to settle for hour, when the deposited carmine is carefully collected, drained, and dried.
Cochineal Lake.—(a) Digest 1 oz. coarsely powdered cochineal in 2i oz. each water and rectified alcohol for a week ; filter, and precipitate by adding a few drops of tin solution every 2 hours, till the whole of the colouring matter is thrown down; wash the precipitate iu distilled water, and dry.
(b) Digest powdered cochineal in ammonia water for a week ; dilute with a little water, and add the liquid to a solution of alum as long as any precipitate (lake) falls. (c) Boil 1 lb. coarsely powdered cochineal in 2 gal. water for 1 hour ; decant, strain, add solution of 1 lb. cream of tartar, and precipitate with solution of alum. By adding the alum first and precipitating the lake with the tartar, the colour is slightly changed.
Indian .Red.—(a) Sulphate of iron is calcined until the water of crystallization is expelled, then roasted by a fierce fire until acid vapours cease to arise, cooled, washed with water till the latter has no acid reaction, and dried. (b) Calcine 11 parts common salt with 25 parts green sulphate of iron ; well wash with water, dry, and powder. (c) The finest Indian red or " crocus" usually undergoes a second calcination at a higher temperature.
Madder Lake.— (a) Tie 2 oz. madder in a cloth, beat it well in a pint of water in a stone mortar, and repeat the process with about 5 pints of fresh water till it ceases to yield colour ; boil the mixed liquor in an earthen vessel, pour into a large basin, and add 1 oz. alum dissolved in 1 pint boiling water ; stir well, and gradually pour in oz. of strong solution of carbonate of potash ; let stand until cold, pour off the yellow liquor from the top, drain, agitate the residue repeatedly in 1 qt. boiling water, decant, drain, and dry. (b) Add a little solution of acetate of lead to a decoction of madder, to throw down the brown colon' ing matter ; filter, add solution of tin or alum, precipitate with solution of carbonate of soda or potash, and proceed as before. (c) Macerate 2 lb. ground madder in 1 gal. water for 10 minutes ; strain and press quite dry ; repeat a second and third time, and add to the mixed liquors lb. alum dissolved in 3 qt. water ; heat in water-batb for 3-4 hours, adding water as it evaporates ; filter first through flannel, and when cold enough through paper ; add solution of carbonate of soda as lung as precipitate falls ; wash the latter till the water comes off colourless, and dry.