Alcohol unites thus readily not only with resins and with water, but with oils and balsams; these compounds form the extensive class of elixirs, tinctures, quintessences, &c. EMILY. I suppose that alcohol must be highly combustible, since it contains so large a proportion of hydrogen? MRS. B. Extremely so; and it will burn at a very moderate temperature. CAROLINE. I have often seen both brandy and spirit of wine burnt; they produce a great deal of flame, but not a proportional quantity of heat, and no smoke whatever. MRS. B. The last circumstance arises from their combustion being complete; and the disproportion between the flame and heat shows you that these are by no means synonymous. The great quantity of flame proceeds from the combustion of the hydrogen to which, you know, that manner of burning is peculiar. --Have you not remarked also that brandy and alcohol will burn without a wick? --They take fire at so low a temperature, that this assistance is not required to concentrate the heat and volatilise the fluid. CAROLINE. I have sometimes seen brandy burnt by merely heating it in a spoon. MRS. B. The rapidity of the combustion of alcohol may, however, be prodigiously increased by first volatilising it. An ingenious instrument has been constructed on this principle to answer the purpose of a blow-pipe, which may be used for melting glass, or other chemical purposes. It consists of a small metallic vessel (PLATE XIV. Fig. 2.), of a spherical shape, which contains the alcohol, and is heated by the lamp beneath it; as soon as the alcohol is volatilised, it passes through the spout of the vessel, and issues just above the wick of the lamp, which immediately sets fire to the stream of vapour, as I shall show you-- EMILY. With what amazing violence it burns! The flame of alcohol, in the state of vapour, is, I fancy, much hotter than when the spirit is merely burnt in a spoon? MRS. B. Yes; because in this way the combustion goes on much quicker, and, of course, the heat is proportionally increased. --Observe its effect on this small glass tube, the middle of which I present to the extremity of the flame, where the heat is greatest. CAROLINE. The glass, in that spot, is become red hot, and bends from its own weight. MRS. B. I have now drawn it asunder, and am going to blow a ball at one of the heated ends; but I must previously close it up, and flatten it with this little metallic instrument, otherwise the breath would pass through the tube without dilating any part of it. --Now, Caroline, will you blow strongly into the tube whilst the closed end is red hot. EMILY. You blowed too hard; for the ball suddenly dilated to a great size, and then burst in pieces. MRS. B.