In addition to the painting colours, there are a few metals which are used to enrich pottery; unfortunately, the number of those which can undergo exposure to a red heat without oxidizing is very limited. There are only three, viz. gold, silver, and platinum, which can stand it, and, among these, silver is of little use, on account of its proneness to tarnish under the action of sulphurous gases. Gold, on the contrary, affords to the decorator one of his greatest resources. We cannot say when the Chinese began to use it; we only know that in Europe it was thought a great discovery, when, in the sixteenth century, it was used in the Italian majolica. From that time to the introduction of hard and soft porcelain in Europe, it was rarely and sparingly used; and it was at Meyssen, soon followed by the other continental and English manufactories, that they began to use it extensively. At the present time, its annual consumption by our Staffordshire potters alone represents a very large sum of money. There are several ways of preparing gold for pottery purposes; the oldest consists in grinding gold leaves on a slab, adding to it gum water, honey, or any other mucilaginous liquid. This laborious process surpasses all others; it has a very artistic effect when used thin, in the Chinese fashion, and, when laid thick, as we find it in the Old SA"vres ware, it answers beautifully for chasing; the only drawback is the expense. The most usual way is to have it amalgamated with mercury, and afterwards ground in turpentine; it has then the appearance of a blackish substance, which will regain its colour, as soon as the mercury is volatilized by the application of a gentle heat. When it comes out of the kiln, the gold is dull, and requires to be burnished with agate and bloodstone tools, to be in possession of all its brightness.