|
|
Two species of scale insects: cochineal and kermes
|
|
Natural variety of pigment
|
Cochineal: Extraction of the insect material with hot water and reaction with sulfuric acid. The precipitation of the hot extract with an alum solution results in a red cochineal lake.
|
|
19th century recipe
|
Superfine Carmine of Amsterdam.
Heat 6 buckets of rain-water, and when it commences to boil throw in 2 lbs. of finely-powdered cochineal; continue boiling 2 hours, and then add 3 oz. of pure water, and immediately afterwards 4 oz. of binoxalate of potash. Boil again 1 minute, then remove the vessel from the fire, and let the decoction stand 4 hours. Draw off the supernatant liquid with a syphon into numerous basins, and put them aside upon a shelf for about 3 weeks, at the end of which time a mouldy pellicle will be formed, which is to be carefully removed with a whalebone, or by means of a small sponge attached to the end of a stick. The water is then run off through a syphon, which must reach to the bottom of the pans, the carmine being so compact that it adheres. This carmine is dried in the shade, and is of an intensely brilliant hue.
Carmine Lake
Boil 2 oz. of cochineal in 1 pt. of water, filter the solution through paper, and add 2 oz. of pearlash dissolved in 1/2 pint of warm water and filtered through paper. Make a solution of cuttlebone, as in the former process, and to 1 pt. of it add 2 oz. of alum dissolved in 1/2 pt. of water. Put this mixture gradually to the cochineal and pearlash as long as any ebullition arises, and proceed as above.
|
 |
|
|
|