Of the various forms of adulteration practiced in China and Japan artificial coloring or “facing” is perhaps the most prevalent and glaring. The material used for the purpose is usually composed of Prussian blue, gypsum, indigo, turmeric, and more frequently, China clay, a whitish iridescent powder, resembling mica, variously composed, but generally consisting of _kaolin_ (soapstone), and sulphate of lime. While that in use in Japan is not known, its composition being a secret, known only to the manufacturers, but is evidently a preparation of gypsum and kaolin, the Japanese contending that it is a vegetable compound pure and simple. That kaolin is used in its preparation can hardly be denied, as kaolin contains sulphur, and many of the lower grades of Japan teas are found on infusion to possess a slightly sulphurous odor. It has been proved, however, whatever its nature, to be less harmful and injurious than the Chinese compound, and used only in the manipulation and sophistication of the lower or commoner grades of tea in that country. The process of coloring or facing Green teas is performed by placing a portion of Prussian blue in a porcelain bowl, not unlike a chemist’s mortar, and pulverizing it into a fine powder, a small quantity of gypsum being meanwhile burned over a charcoal fire, to soften it, after which it is ground fine. The two substances are next mixed together, in the proportions of one part blue to four parts gypsum, both making in combination a light-blue preparation, in which state it is applied to the leaves during the last process of firing, about five minutes prior to removal from the pans, the time being regulated by a burning joss stick. The Saihoo taking a handful of the compound, scatters it over the leaves while in the pans, other operators tossing and turning the leaves around rapidly with their hands meantime in order that it may equally diffuse among them. One ounce of coloring-matter will face fifteen pounds of leaves, imparting to them a dull leaden-blue hue, and “glossy” or greasy appearance, readily detected in the hand. In many districts, most notably in Ningpo and Canton, turmeric, kaolin, and China clay are more extensively employed for the purpose. This almost transparent form of adulteration is readily detected in the following manner:—