1. A paste composed of a sandy and a white argillaceous earth, and some alkali or flux, greatly varying in their relative proportions, and producing degrees of fineness and hardness from a coarse sandy earthenware to a semi-vitrified translucent body, the latter being in fact a kind of porcelain of artificial paste. 2. A glaze formed as a true glass, of siliceous sand and an alkali (potash or soda), with the addition in some cases of a small quantity of oxide of lead or other flux. Such is the general, but by no means the constant, definition of the component ingredients of all the varieties rightly classed together as members of this group, for there can be no doubt that great variations occurred in their composition at different periods and places, and some examples of the finer kinds of Persian, Arabian, and perhaps of Damascus wares are met with in, or under, the glaze of which the oxide of tin has been used to produce a white and more even surface. A large amount of information about Persian ware is conveyed to us in the work of the comte de Rochchouart who, during a residence of some years in Persia, gave great attention to its ceramic productions of former and of present times. After establishing the fact of the former production of at least four distinct kinds of Kaolinic porcelain, he minutely describes ancient varieties of faience of which the polychrome pieces are the more rare, the blue and white less so; he mentions one uncommon variety, believed to have been made at Cachan, as having a paste of red earth covered with a stanniferous enamel of great beauty, and painted in cobalt under a glaze highly baked; they ring like metal. We do not recollect having seen an example of this variety. Marks imitating those on Chinese porcelain occur on pieces painted in cobalt blue on white. He further tells us that the ancient faience of Persia is as admirable as the modern is detestable, notwithstanding it retains a degree of oriental elegance. The industry at present is carried on at Nahinna; at Natinz, where pottery has been made for some hundred years, and where some of the finest was produced but now inferior; at Cachan, turquoise blue, and many-coloured; while Hamadan, Kaswine and Teheran make inferior wares, the latter being the worst. We do not derive any information from M. de Rochchouart on the subject of the lustred wares, except in his description of the tiles of the mosque of Natinz of the 12th century; nor do we learn anything of that variety of creamy white pottery having the sides pierced through the paste but filled with the translucent glaze, and which is believed to be the Gombrōn ware of Horace Walpole’s day. But he gives interesting information on the subject of the tiles used for decoration, of which the finest are those mentioned above; those of Ispahan and of the period of Shah Abbas (1585-1629) being also admirable for their exquisite design.