80. TO KINDLE A FIRE UNDER WATER.--Put into a deep wine-glass, that is small at the bottom, three or four bits of phosphorus, about the size of flax seeds, and two or three times the quantity of chlorate of potass, in grains or crystals, and fill the glass nearly full of water. Then place the end of a tobacco-pipe stem directly on, or over the chlorate and phosphorus, and pour nearly a tea-spoon full of sulphuric acid into the bowl of the pipe, that it may fall directly on the phosphorus; a violent action will ensue, and the phosphorus will burn vividly, with a very curious light under the water. 81. TO LIGHT A CANDLE BY APPLICATION OF ICE.--Attach to the wick of a candle, a small piece, or globule of potassium (the metallic base of potass) of the size of a small shot. Apply an icicle or point of ice to the metal, and it will instantly inflame. _Note._--This curious substance, which has the peculiar property of being ignited by coming in contact with ice or water, has been lately discovered by Sir Humphrey Davy. It is produced by making pure potass a part of the circuit of a powerful Voltaic battery. It cannot be preserved but by being kept immersed in naptha, a kind of oil of which oxygen is not a constituent. 82. TO FORM LETTERS OR FLOWERS OF REAL FLAME.--Provide a tin chest of about eighteen inches in length, equal in height and one inch in breadth. Chalk any design, of letters or flowers on the face of this chest, and pierce each line with rows of small holes, which should be about half an inch distant from each other.--Make an aperture at the top, through which pour about a pint of a mixture of rum and spirits of turpentine. Place two or three lamps under the bottom of the chest (which must be raised a little from the floor for that purpose) to warm the spirits, but not so as to cause them to boil. Stop the aperture at the top and after eight or ten minutes (which time should be allowed for the vapour to expel the atmospheric air, which otherwise would cause an explosion) apply the flame of a lamp to the pierced lines;--in an instant, all the lines will be covered with flame, which will continue till the spirits are exhausted.