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Thinking that the worms might possibly perceive and dislike the smell or taste of the shell-lac, though this was very improbable, especially after the leaves had been left out during several nights, the tips of the needles of many leaves were tied together with fine thread.
Dissolve 1 oz. of common salt in 1 quart of water, bring to a boil, and put in 1-1/4 lbs. gum shell-lac; when it shall have dissolved, pour into cold water, and work like wax; make into small sticks. This will make crockery as firm as a rock. Directions: Warm the stick, apply it to the broken edges, then heat the edges, place them together and hold for a minute, and they are firm.
The jungle I found to consist chiefly of thorny bushes, Jujube of two species, an Acacia and Butea frondosa, the twigs of the latter often covered with lurid red tears of Lac, which is here collected in abundance. As it occurs on the plants and is collected by the natives it is called Stick-lac, but after preparation Shell-lac.
Let us follow out this notion; consider, he argues, the case of a non-conductor of electricity, such for example as shell-lac, with its molecules, and intermolecular spaces running through the mass. In its case space must be an insulator; for if it were a conductor it would resemble 'a fine metallic web, penetrating the lac in every direction.
Having thus prepared the varnish or japan, clean well the substance which is to be japanned; then lay vermillion, tempered with shell-lac varnish, or with drying oil, very thinly diluted with oil of turpentine, on the places intended to imitate the more transparent parts of the tortoise-shell; when the vermillion is dry, brush the whole over with black varnish, tempered to a due consistence with the oil of turpentine.
The tips of a large number of needles of P. austriaca were cemented together with shell-lac dissolved in alcohol, and were kept for some days, until, as I believe, all odour or taste had been lost; and they were then scattered on the ground where no pine-trees grew, near burrows from which the plugging had been removed.
The modern sealing-wax, whose distinctive is shell-lac, was brought by the Dutch from India to Europe; and the earliest seals date from about A.D. 1560. They called it Ziegel-lak, whence the German Siegel-lack, the French preferring cire-a-cacheter, as distinguished from cire-a-sceller, the softer material.
Dissolve in an iron kettle, one part of pearl-ash in about 8 parts of water; add one part of shell-lac, and heat the whole to ebullition. When the lac is dissolved, cool the solution, and impregnate it with chlorine, till the lac is all precipitated.
Shell-lac varnish is the best spirit varnish we have, and may be made any colour by the above process. The English method of preparing the colour in size, which serves as the ground on which the gold is laid, is, to grind together some red oxide of lead with the thickest drying oil that can be procured, the older the better.
But the fact is that it resembles the wax of black sealing-wax, which surrounds and insulates the particles of conducting carbon, interspersed throughout its mass. In the case of shell-lac, therefore, space is an insulator. But now, take the case of a conducting metal. Here we have, as before, the swathing of space round every atom.
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