Carmine

Carmine (Arabic Kermes) is the red colouring principle obtained from the cochineal insect (see COCHINEAL). The method by which it is prepared is said to have been accidentally discovered by a Franciscan monk at Pisa, while compounding a medicine containing cochineal; and in 1656 its manufacture was begun. There are several processes by which carmine may be prepared, all of which in effect depend on exhausting powdered cochineal with boiling water, and precipitating the pigment by the addition of a weak acid or an acid salt. The following is an example of the processes: Digest 1 lb. of cochineal in 3 gallons of water for 15 minutes, then add 1 oz. of cream of tartar, heat gently for 10 minutes, add $\backslash frac\{1\}\{2\}$ oz. of alum, boil for 2 or 3 minutes, and after allowing impurities to settle, the clear liquid is placed in clean glass pans, when the carmine slowly separates and deposits. After sufficient time the liquid is drained off, and the pigment is dried in the shade. It is alleged that bright sunny weather is essential to the production of the finest qualities. Hence it is said the United Kingdom is unfavourably situated for the manufacture; but the fact is that details of successful processes are guarded with jealous care; and in all probability brightness and purity of product are due to important minor details in the manufacturing process. Carmine is soluble in water, weak spirit, and in ammoniacal solutions; the latter agent affording a ready means of detecting the presence of the adulterants—chalk, China clay, and vermilion—frequently added to the costly pigment. Carmine is a most beautiful pinky red, sometimes used for silk and wool dyeing, but more sought for colouring fine confections, and dyeing feathers and artificial flowers; and it is not unknown as cosmetic rouge. Carmine Lake, prepared with alumina, is a most important artist's colour. There are various other tinctorial agents known under the name of carmine, of which the commonest are Archil Carmine made from Archil (q.v.); Brilliant Carmine Red, a lake of Brazil-wood; Indigo Carmine, a purple preparation of indigo, and Sorgho Carmine, obtained from the juice of the sugar or Chinese Sorghum, Sorghum Saccharatum.