Gutta-percha is a substance possessing many useful and valuable properties; it was unknown in Europe until within a very recent date, though it is said to have been in common use, for a long period previous to our discovery of its utility, amongst the natives of the Indian Archipelago, chiefly for making axe-handles. It is the concrete juice of a large tree, supposed to be the _Isonandra Gutta_, and is brought to Europe in irregular masses of a brown color, and contains various impurities which are easily got rid of by working it in hot water. Gutta-percha possesses the desirable properties of being solid, slightly elastic, not brittle, and very tough, capable of being melted at the heat of boiling water, and being drawn out or moulded into almost any form; it resists the action of water and spirits, unless very strong, oils, alkalies, and weak acids, but spirits of turpentine, chloroform, and naptha, each dissolve it. A substance which has so many valuable properties as these, of course enters into a multiplicity of forms and uses. WAX. This useful substance is produced by bees for the purpose of building their comb, which consists of hexagonal cells made of wax; which substance they secrete in scales, between the sections of the abdomen, and draw out for building their beautiful cells. When the honey is drained off from the comb, this is washed and melted, it then constitutes the yellow wax of commerce, commonly called “bee’s-wax.” To make this into the white wax it is boiled in water, spread out into thin layers, and exposed to the light and air; this is repeated until all the color has gone and the wax remains pure and white. Pure wax is a soft-feeling substance, harder than tallow, and not greasy to the touch; it is easily melted, and burns with a clear white flame, hence its most general use--namely, that of making candles; it is not soluble in water, but unites with oils and fats. NITRE. This substance, known also in commerce by the name of saltpetre, is brought to this country from India, where in certain places, it forms a sort of efflorescence on the soil; this is taken off together with the surface of the soil, and mixed with water, which, after all the earth has subsided holds the nitre in solution. The water is then evaporated and the nitre crystallizes in six sided prisms.