Gilding, the art of spreading, or covering any substance with! gold, either in leaf, or in a liquid state.

This art was known to the ancients, though it has only within. the last two or three centuries been brought to the highest degree of. perfection. Consistently with our plan, we cannot enter into the various branches of gilding, theknow-ledge of which is confined to a particular class of artists; yet, as there are many who delight in making experiments, we shall subjoin a simple method, that may be easily practised, and will not affect the health of individuals.

Let gold be dissolved in aqua-regia (which see) : in this solution pieces of linen should be immersed, then dried, and burnt to ashes; these should be finely pulverized, and rubbed on silver, by means of a wet linen rag, or more properly with a moistened piece of cork : thus, the particles of gold they con-fain will be deposited, so as to adhere firmly to the silver. The remaining ashes are next to be washed off, and the surface of the silver that does not appear gilt, is to be burnished with a blood-stone, till B b It it acquires the colour of gold.— This method, which is easy, and consumes a very small portion of gold, is usually employed for the gilding of trinkets, spoons, snuff-boxes, and other articles.

Gold is likewise used for ornamenting glass, porcelain, and other vitrified matters ; to the surface of which (being very smooth, and susceptible of a perfect contact), the gold leaves closely adhere. The pieces are then exposed to a certain degree of heat, and slightly burnished, in order to give them lustre.

However ingenious and pleasing to its amateurs, the art of gilding is very detrimental to the health of the persons who practise it, especially in the more complex branches, where mercury and other noxious minerals are employed over fires, and cannot fail to produce the most pernicious vapours. Gilders by profession are particularly liable to suffer from these exhalations, the influence of which, however, might be effectually prevented, by allowing a continual current of air to perflate the apartment, where the process is managed. Such an arrangement may be easily made, by merely opening the upper window, or a door, which will admit fresh air to pass through the room. By this simple expedient, the tremors, paleness, and sickness usually attendant on such operations, will be completely averted.