Insect manufactures

by Anonymous

There are four sorts of lac known in commerce, but these are only so many different preparations of the same substance. Stick lac is the lac in its natural state, with much of the woody parts of the branches adhering to it: this is collected in the East twice a year, the only trouble being to break off the twigs and branches, and take them to the nearest market, with the lac upon them; or, if destined for exportation, the lac is separated from the larger branches for convenience of freight.

Seed lac is the second description known in commerce. This is a collection of granules, obtained from the former after the colouring matter has been extracted by water, but this is seldom imported, being manufactured into shell lac in India. Lump lac is the third form, being merely the granules further purified and made into lumps. Lastly, there is shell lac, in which the substance is purified to the utmost by being put in bags and held over a fire until sufficiently melted to pass through the pores of the linen. The bags are then pressed and squeezed at the same time that they are passed over a smooth surface of wood, thus depositing the lac in thin layers. The fineness and purity of the lac will of course depend on the fineness of the bag through which it is passed. Shell lac if pure will take fire when laid on a hot iron, and will burn with a strong but not disagreeable smell. The heat of the ship’s hold is very apt to run this commodity into a solid mass, in which case its value is much depreciated.

The different kinds of lac are largely used by Indians for ornamental purposes. Of the lump lac they make bangles, or armlets for women of the lower class; shell lac being employed for the same kind of ornaments for the upper classes, and also for beads, chains, necklaces, and other adornments. They also make a good varnish by melting the lac, colouring it with cinnabar or some other pigment, and making it into sticks like our sealing wax. The box, cabinet, or other article about to be varnished, is made hot by a charcoal fire, and then rubbed over with a stick of lac, the surface being afterwards smoothed with a piece of folded plantain leaf to make it equal. A similar varnish is often used on images and ornamental figures. The religious houses of the Indians are often adorned with very thin beaten lead, coloured with various varnishes made from lac. The leaf of lead is laid upon a smooth heated iron while the varnish is being applied.

Lac is also extensively used as a dye. By pouring warm water on stick lac, a crimson solution is obtained, which is the source of much of the value attached to lac. This colouring matter is extracted in various ways, and made into small square cakes for sale; these go by the names of lac dye, lac lake, or cake lake. When broken, the cakes are dark coloured, shining, smooth and compact, and when scraped or powdered they present a bright red colour approaching carmine. The native mode of dyeing with this substance is described as follows. They take one gallon of the red liquid, and add to it three ounces of alum. Three or four ounces of tamarinds are boiled in a gallon of water and strained. Equal parts of the red liquid and of the tamarind water are then mixed over a brisk fire; and the pieces of silk or cotton cloth to be dyed are dipped and wrung alternately, until they have received a proper proportion of the dye. To deepen the colour they increase the proportion of the red liquid, and lengthen the time during which the cloth remains immersed in it. The colour is rendered permanent by the use of bark in the rinsing water.

There is yet another and a singular employment of lac among the Indians. The polishing grindstones used by eastern lapidaries are composed of a mixture of three parts river sand with one part lac: these are mixed in a vessel over the fire, and then formed into the shape of a grindstone; the part of the lac being merely that of a cement to hold the sand together.

In this country lac is valuable partly as a dye, partly as a varnish. As a dye it is less beautiful, but more durable than cochineal. It forms the best kinds of sealing wax, and is also used in the hat manufacture.

With regard to its use as a dyeing drug we find the following remarks in the Entomology of Kirby and Spence. “It has been employed to impart a blood red or crimson dye to cloth from the earliest ages, and was known to the Phœnicians before the time of Moses, under the name of Tola or Thola, to the Greeks under that of Coccus, and to the Arabians and Persians under that of Kermes or Alkermes; whence, as Beckmann has shown, and from the epithet vermiculatum given to it in the middle ages, when it was ascertained to be the produce of a worm, have sprung up the Latin coccineus, the French cramoisi and vermeil, and our crimson and vermilion. It was most probably with this substance that the curtains of the tabernacle (Exodus xxvi.) were dyed deep red, (which the word scarlet, as our translators have rendered it, then implied, not the colour now so called, which was not known in James the First’s reign, when the Bible was translated;)—it was with this that the Grecians and Romans produced their crimson; and from the same source were derived the imperishable reds of the Brussels and Flemish schools. In short, previous to the discovery of cochineal, this was the material universally used for dyeing the most brilliant red then known; and though that production of the New World has, in some respects undeservedly, supplanted it in Europe, where it is little attended to except by the peasantry of the provinces in which it is found, it still continues to be employed in great part of India and Persia.

Some other insects besides the cochineal and lac insects are found to produce dyes. The galls of a peculiar species of aphis are used in the Levant, Persia and China, for dyeing silk crimson, and it is thought that the galls of another species of this insect, common on the fir trees of this country, might be employed for a similar purpose. A species of mite is employed in Guinea and Surinam as a dye, and it is suggested that the beautiful little dazzling red mite which is common here, might also yield a valuable tincture. Réaumur has even suggested that water colours of beautiful tints not otherwise easily attainable, might be procured by feeding the common clothes-moth on different coloured wools. The excrement of this insect always retains the colour of the substance forming the food, and mixes well with water to form a pigment.

NUT GALLS AND THE GALL INSECT.