The Inc obtained in the foregoing process is to be dissolved in a pint of alcohol, more or less, according to the required strength of the varnish; and after standing for some time in a gentle heat, the clear liquor, which is the varnish, is to be poured off from the sediment.
Mr. Lunuag's is as follows :—Dissolve five ounces of shell-lac in a quart of rectified spirits of wine; boil for a few minutes, with ten ounces of well-burnt and recently heated animal charcoal, when a small quantity of the solution should be drawn off and filtered; if not colourless, a little more char coal must be ridded. When all colour is removed, press the liquor through silk, as linen absorbs more varnish, and afterwards filter it through tine blotting paper. In cases where the wax found combined with the lac is objectionable, filter cold ; if the wax be not injurious, filter while hot. This kind of varnish should be used in ta temperature of not less than 60P Fehr.; it dries in a few minutes, and is not afterwards liable to chill or bloom ' • it is therefore particularly applicable to drawings and prints which have been sized, and may be advantageously used upon oil paintings which have been painted a sufficient time, as it bears out colour with the purest effect. This quality
prevents it from obscuring gilding, and renders it a valuable leather varnish to the book-binder, to whose use it has already been applied with happy effect, as it does not yield to the warmth of the hand, and resists damps, which 'abject bindings to mildew. Its useful applications are very numerous, indeed, to all thepurposes of the best hard spirit varnishes: it is to be used under the same conditions, and with the same management. Common seed-lac varnish is usually made by digesting eight ounces of the bright, clear grained lac in a quart of spirits of wine, in a wide-mouthed bottle, putting it in a warm place for two or three days, and occasionally shaking it. When dissolved it may be strained then_ into another bottle for use. In India, lac is fashioned into rings,and other trinkets. Its colouring matter, which is soluble in water, is employed as a dye. The resinous portion is mixed with about three times its weight of finely powdered sand, to form polishing stones. The lapidaries mix powder of corundum with it in a similar manner.