Thus arranged, the lamp is to be lighted and allowed to burn until the platinum becomes red hot; the flame may then be blown out, nevertheless the platinum remains incandescent for an indefinite period. The proximity of a red-hot ball to a material of the physical quality of Eau de Cologne, diffused over a surface of cotton wick, as a matter of course causes its rapid evaporation, and as a consequence the diffusion of odor. Instead of the lamp being charged with Eau de Cologne, we may use Eau de Portugal, vervaine, or any other spirituous essence. Several perfumers make a particular mixture for this purpose, which is called EAU A BRULER. Eau de Cologne, 1 pint. Tincture of benzoin, 2 oz. " vanilla, 1 oz. Otto of thyme, } " mint, } of each, 1/2 drachm. " nutmeg, } Another form, called EAU POUR BRULER. Rectified spirit, 1 pint. Benzoic acid, 1/2 oz. Otto of thyme, } of each, 1 drachm. " caraway, } " bergamot, 2 oz. Persons who are in the habit of using the perfume lamps will, however frequently observe that, whatever difference there may be in the composition of the fluid introduced into the lamp, there is a degree of similarity in the odor of the result when the platinum is in action. This arises from the fact, that so long as there is the vapor of alcohol, mixed with oxygen-air, passing over red-hot platinum, certain definite products always result, namely, acetic acid, aldehyde, and acetal, which are formed more or less and impart a peculiar and rather agreeable fragrance to the vapor, but which overpowers any other odor that is present. FUMIGATING PAPER. There are two modes of preparing this article:-- 1. Take sheets of light cartridge paper, and dip them into a solution of alum--say, alum, one ounce; water, one pint. After they are thoroughly moistened, let them be well dried; upon one side of this paper spread a mixture of equal parts of gum benzoin, olibanum, and either balm of Tolu or Peruvian balsam, or the benzoin may be used alone. To spread the gum, &c., it is necessary that they be melted in an earthenware vessel and poured thinly over the paper, finally smoothing the surface with a hot spatula. When required for use, slips of this paper are held over a candle or lamp, in order to evaporate the odorous matter, but not to ignite it. The alum in the paper prevents it a to certain extent from burning. 2. Sheets of good light paper are to be steeped in a solution of saltpetre, in the proportions of two ounces of the salt to one pint of water, to be afterwards thoroughly dried. Any of the odoriferous gums, as myrrh, olibanum, benzoin, &c., are to be dissolved to saturation in rectified spirit, and with a brush spread upon one side of the paper, which, being hung up, rapidly dries.