In the meantime in China itself, both in connection with the embassies at Pekin and among some of the merchants at Shanghai and other treaty ports, much information was being collected, and it was above all the merit of Franks to keep himself in communication with and to encourage all such research. Dr. Hirth, long in the service of the Chinese at Shanghai and elsewhere, has published a series of learned studies treating of the relation of the Chinese to the Roman empire, of the Arab traders during the Middle Ages, and of the early history of Chinese porcelain generally. But it is to a former member of our embassy at Pekin, to Dr. Bushell, that we are above all indebted for the throwing open of Chinese sources of information upon the history of porcelain. A worthy successor of the Père D’Entrecolles in his intimate acquaintance with the country and its language, Dr. Bushell is well abreast of the chemical and technical knowledge of the day, and his position as physician to our embassy at Pekin has given him access to information from the best Chinese sources, as well as to the treasures of many of the native collections of the capital. Dr. Bushell has written the text to a sumptuously illustrated work, nominally a catalogue of the collection of porcelain formed by the late Mr. Walters of Philadelphia, and into this text he has woven all the vast wealth of material that he had accumulated during many years of study both at Pekin and in Europe. This work has thus superseded all other sources of information on the history and manufacture of Chinese porcelain. He has, in fact, ransacked all that has been written in China on these subjects, and his translations have this advantage over the works of Julien, that they are made by one who knows thoroughly the subject that the Chinese author is dealing with. We must not forget the researches on the chemical and technical side of the subject by what we may call the school of Sèvres. To these workers we have made frequent reference in previous chapters. It is to the experiments and analyses of men such as Brongniart, Salvétat, Ebelmen, and Vogt, that we are indebted for our knowledge of the chemical constitution of the paste, the glaze, and the enamels of Chinese porcelain, as well as for a rational exposition of the methods of its manufacture. To sum up, our sources of information of late years are, in the main, English, as far as the history and what I may call the sinology of our subject are concerned; but for the chemistry and technology we must turn to French works. As far as I know, little of value has been published in Germany on the subject of Oriental porcelain. The discussion between Karabacek, Meyer, and Hirth (whose later papers have been published in German) on the early history of celadon and on the Arab traders of the Middle Ages, is perhaps the most notable exception.