"I have stated that the plants grown in the districts of Chekiang produce green teas, but it must not be supposed that they are the green teas which are exported to England. The leaf has a much more natural color, and has little or none of what we call the 'beautiful bloom' upon it, which is so much admired in Europe and America. There is now no doubt that all these 'blooming' green teas, which are manufactured at Canton, are dyed with Prussian blue and gypsum, to suit the taste of the foreign 'barbarians;' indeed the process may be seen any day, during the season, by those who give themselves the trouble to seek after it. It is very likely that the same ingredients are also used in dyeing the northern green teas for the foreign market; of this, however, I am not quite certain. There is a vegetable dye obtained from _Isatis indigotica_ much used in the northern districts, and called _Teinsing_; and it is not unlikely that it may be the substance which is employed. The Chinese never use these dyed teas themselves, and I certainly think their taste in this respect is more correct than ours. It is not to be supposed that the dye used can produce any very bad effects on the consumer, for, had this been the case, it would have been discovered before now; but if entirely harmless or inert, its being so must be ascribed to the very small quantity which is employed in the manufacture." In short, the black and green teas which are generally exported to England and the United States from the northern provinces of China, are made from the same species; and the difference of color, flavor, &c., is solely the result of the different modes of preparation. I shall make an extract, also, from Williams's "Middle Kingdom:"--