Indian Lake

Synonyms:

Indian Lake, Lac Lake, Lack-Lack

Lac is a resinous secretion produced by certain plants when punctured by the larvæ of the Coccus lacca, an East Indian hemipterous insect. Amongst the trees which the insect chiefly attacks are Butea frondosa, Ficus religiosa, and F. bengalensis, Schleichera trijuga, Shorea robusta, and Zizyphus jujuba. The lac, though a secretion primarily derived from the tree on which the insects feed, is yet profoundly modified, particularly with respect to its colour, during its passage through the animal's body. It varies in colour with the species of tree, but always consists mainly of three substances - namely, a resin, a colouring matter, and a wax. The resin, which constitutes two-thirds of the substance, is obtained in the form known as 'seed-lac' by pounding in water the lac which has been removed by pressing with a roller the encrusted twigs on a floor. The water becomes red; from it, by evaporation, the crude 'lac-dye' is obtained. This is made into cakes, and dried.

The lac-dye of commerce contains nitrogenous and mineral matters, as well as several dark-coloured impurities, and some resin. In order to prepare a lake from it, it should be first powdered, and then digested in spirit of turpentine, or benzene. The purified residue is, when dry, extracted with sodium carbonate solution: the liquor is afterwards filtered and precipitated with alum solution. The precipitate thus formed is washed and dried in the dark.

Indian lake was used by the Venetian and Flemish painters of the sixteenth century, but it does not seem, so far as one can gather from the notices of it in the work of De Mayerne, and in the Secreet-Boeck, to have been often obtained of good colour. It is even spoken of as a 'light brown.'

Indian lake is inferior in beauty, and in variety of hues, to the colours from madder; it is also more affected by light. But it is distinctly less fugitive than crimson lake and the other cochineal pigments.

I do not know from direct experiment whether the comparative stability of the red colouring matter from kermes when used as a dye for animal fibres belongs also to all the lakes prepared from this substance: anyhow, kermes pigments are, so far as I can learn, not met with in commerce at the present time. Their use in European painting seems to have been displaced, first of all by Indian lac lakes, and then by cochineal lakes. The colouring matters produced by these three kinds of coccus are closely allied chemically.