re also divided into those of fresh water and those of salt. Dr Halley is of opinion, that all great perennial lakes are saline, either in a greater or less degree; and that this saltness increases with time: and on this foundation he proposes a method for determining the age of the world.

Large lakes answer the most valuable purposes in the northern regions, the warm vapours that arise from them moderating the pinching cold of those climates; and, what is still a greater advantage, when they are placed in warmer climates at a great distance from the sea, the exhalations raised from them by the sun cause the countries that border upon them to be refreshed with frequent showers, and consequently prevent their being barren deserts.

LAQUE, or Lacque, a preparation of different substances into a kind of magisterial for the use of painters. One of the finest and first invented of which was that of gum lacca or lacque; from which all the rest, as made by the same process, are called by the common name lacquer. See LACCA.

The method of preparing these in general may be known Lake known by the example of that of the curcuma root of the hops, called turmeric root; the process for the making of which is this: Take a pound of turmeric root in fine powder, three pints of water, and an ounce of salt of tartar; put all into a glazed earthen vessel, and let them boil together over a clear gentle fire, till the water appears highly impregnated with the root, and will stain a paper to a beautiful yellow. Filter this liquor, and gradually add to it a strong solution of rock alum in water, till the yellow matter is all curdled together and precipitated; after this pour the whole into a filter of paper, and the water will run off and leave the yellow matter behind. It is to be washed many times with fresh water, till the water comes off infusible, and then is obtained the beautiful yellow called lacque of turmeric, and used in painting.

In this manner may a lake be made of any of the tinging substances that are of a somewhat strong texture, as madder, logwood, &c., but it will not succeed in the more tender species, as the flowers of roses, violets, &c., as it destroys the nice arrangement of parts in these subjects on which the colour depends.

A yellow lake for painting is to be made from broom flowers in the following manner: Make a ley of pot ashes and lime reasonably strong; in this boil, at a gentle fire, fresh broom flowers till they are white, the ley having extracted all their colour; then take out the flowers, and put the ley to boil in earthen vessels over the fire; add as much alum as the liquor will dissolve; then empty this ley into a vessel of clean water, and it will give a yellow colour at the bottom. Let all settle, and decant off the clear liquor. Wash this powder, which is found at the bottom, with more water, till all the salts of the ley are washed off; then separate the yellow matter, and dry it in the shade. It proves a very valuable yellow.

Lake is at present seldom prepared from any other substance than scarlet rags, cochineal, and Brazil wood. The best of what is commonly sold is made from the colour extracted from scarlet rags, and deposited on the cuttle-bone; and this may be prepared in the following manner: Dissolve a pound of the best pearl-ashes in two quarts of water, and filter the liquor through paper; add to this solution two more quarts of water and a pound of clean scarlet shreds, and boil them in a pewter boiler till the shreds have lost their scarlet colour; take out the shreds and press them, and put the coloured water yielded by them to the other; in the same solution boil another pound of the shreds, proceeding in the same manner; and likewise a third and fourth pound. Whilst this is doing, dissolve a pound and a half of cuttle-fish bone in a pound of strong aquafortis in a glass receiver; adding more of the bone if it appear to produce any ebullition in the aquafortis; and pour this strained solution gradually into the other; but if any ebullition be occasioned, more of the cuttle-fish bone must be dissolved as before, and added till no ebullition appears in the mixture. The crimson sediment deposited by the liquor thus prepared is the lake; pour off the water; and stir the lake in two gallons of hard spring water, and mix the sediment in two gallons of fresh water; let this method be repeated four or five times. If no hard water can be procured, or the lake appears too purple, half an ounce of alum should be added to each quantity of water before it be used. Having thus sufficiently freed the lake from the salts, drain off the water through a filter, covered with a worn linen cloth. When it has been drained to a proper dryness, let it be dropped through a proper funnel on clean boards, and the drops will become small cones or pyramids, in which form the lake must be suffered to dry, and the preparation is completed.

Lake may be prepared from cochineal, by gently boiling two ounces of cochineal in a quart of water; filtering the solution through paper, and adding two ounces of pearl-ashes dissolved in half a pint of warm water, and filtered through paper. Make a solution of cuttle-bone as in the former process; and to a pint of it add two ounces of alum dissolved in half a pint of water. Put this mixture gradually to that of the cochineal and pearl-ashes, as long as any ebullition appears to arise, and proceed as above. A beautiful lake may be prepared from Brazil wood, by boiling three pounds of it for an hour in a solution of three pounds of common salt in three gallons of water, and filtering the hot fluid through paper; add to this a solution of five pounds of alum in three gallons of water. Dissolve three pounds of the best pearl-ashes in a gallon and a half of water, and purify it by filtering; put this gradually to the other, till the whole of the colour appear to be precipitated, and the fluid be left clear and colourless. But if any appearance of purple be seen, add a fresh quantity of the solution of alum by degrees, till a scarlet hue be produced. Then pursue the directions given in the first process with regard to the sediment. If half a pound of seed lac be added to the solution of pearl-ashes, and dissolved in it before its purification by the filter, and two pounds of the wood, and a proportional quantity of the common salt and water be used in the coloured solution, a lake will be produced that will stand well in oil or water, but is not so transparent in oil as without the seed lac. The lake with Brazil wood may be also made by adding half an ounce of annatto to each pound of the wood; but the annatto must be dissolved in the solution of pearl-ashes. There is a kind of beautiful lake brought from China; but as it does not mix well with either water or oil, though it dissolves entirely in spirit of wine, it is not of any use in our kinds of painting. This has been erroneously called safflower.

Orange Lake, is the tinging part of annatto precipitated together with the earth of alum. This pigment, which is of a bright orange colour, and fit for varnish painting, where there is no fear of flying, and also for putting under crystal to imitate the vinegar garnet, may be prepared by boiling four ounces of the best annatto and one pound of pearl-ashes half an hour in a gallon of water; and straining the solution through paper. Mix gradually with this a solution of a pound and a half of alum in another gallon of water; distilling when no ebullition attends the commixture. Treat the sediment in the manner already directed for other kinds of lake, and dry it in square bits or round lozenges.