FOLIATING of looking-glasses, the spreading the plates over, after they are polished with quicksilver, &c. in order to reflect the image. It is performed thus : a thin blotting paper is spread on the table, and sprinkled with fine chalk : and then a fine lamina or leaf of tin, called foil, is laid over the paper ; upon this mercury is poured, which is to be dis tributed equally over the leaf with a hare's foot, or cotton: dyer this is laid a clean paper, and over that the glass-plate, which is pressed down With the right hand, and the paper drawn gently out with the left : this being done, the plate is covered with a thicker paper, and load en with a greater weight, that the super fluous mercury may be driven out, and the tin adhere more closely to the glass. When it is dried, the weight is removed, and the looking-glass is complete. Foliat ing of globe looking-glasses is done as follows: take five ounces of quicksilver, and one ounce of bismuth ; of lead and tin half an ounce each. First put the
lead and tin into fusion, then put in the bismuth, and wlit'n you perceive that in fusion too, let it stand till it is almost cold, and pour the qnicksilver into it •after this, take the glass globe, which must be very clean, and the inside free from dust ; make a paper funnel, which put into the hole of the globe, as near to the glass as you can, so that the amalgam, when you pour it in, may not splash, and cause the glass to he full of spots ; pour it in gently, and move it about, so that the amalgam may touch every where. If you find the amalgam begin to be eurdly and fixed, then hold it over a gentle fire, and it will easily flow again. And if you find the amalgam too thin, add a little more lead, tin, and bismuth, to it. The finer and clearer your globe is, the better will the looking-glass be.