The palette of the European enameller is a more extensive one, and each large porcelain manufactory has its book of recipes. The composition of the enamels and the relation of the metallic oxides to the fluxes employed have been systematically studied in more than one laboratory. It is only at Sèvres, however, that the results obtained have been made public. It has been the pride of successive generations of chemists--of Brongniart, of Salvétat, of Ebelmen, not to mention living men--to devise fresh sources of colour for the decoration of porcelain. First chromium, then nickel, cadmium, uranium, iridium, and platinum have been added to the list of metals from which enamel pigments have been derived. Among the colours of the muffle-stove the chief gain has perhaps been the discovery of the quality possessed by the oxide of zinc of altering the tints of other metallic oxides with which it is mixed. CHAPTER V THE PORCELAIN OF CHINA Introductory--Classification--The Sung Dynasty (960-1279)--The Mongol or Yuan Dynasty (1280-1368). _‘La porcelaine de la Chine! Cette porcelaine supérieure à toutes les porcelaines de la terre! Cette porcelaine qui a fait depuis des siècles, et sur tout le globe, des passionnés plus fous que dans toutes les autres branches de la curiosité.... Enfin cette matière terreuse façonnée dans les mains d’hommes en un objet de lumière, de doux coloris dans un luisant de pierre précieuse.’_--EDMOND DE GONCOURT, ‘La Maison d’un artiste.’ In any work on porcelain it is something more than the premier place that must be given to the ware of China. We are dealing with an art Chinese in origin, and during a succession of many centuries Chinese in its development. It was only at a comparatively late time that the knowledge of this art spread over the whole civilised world. We in England have, as it were, acknowledged the pre-eminence of that country by adopting the word ‘china’ as an equivalent, more or less, to porcelain.[24] It was under Imperial patronage that the art was developed in China, and the excellence of the porcelain of that country has in a measure varied with the taste and intelligence with which that patronage was exercised in different reigns. The native scholar and connoisseur has for ages been a collector of choice pieces, and his influence has always been exercised in a conservative direction. There is, indeed, in the whole world no such consistent _laudator temporis acti_, and it is this conservative spirit, resulting in a constant ‘returning upon oneself,’ that it is essential to bear in mind if we are to understand the involved relation of the old and the new in the history of the arts of China.