It was the introduction of the felspathic glaze in 1780 that gave the final blow to the effective decoration of Sèvres porcelain. This glaze is made by simply fusing a natural rock (pegmatite) consisting of a mixture of potash felspar with a small quantity of quartz. The ease with which this glaze can be prepared, its hardness and uniformity of surface, led to its universal adoption not only at Sèvres but in the porcelain works of the Limoges district that have for the last hundred years supplied France with ordinary domestic wares--for such use its hardness renders it eminently suitable. But, as we have said, this combination of refractory paste and hard glaze is incompatible with any brilliancy of decorative effect, the enamel colours are quite unable to incorporate themselves with subjacent glaze, they lie dull and dead on the surface, and the faults of the German porcelain are exaggerated. So with the paste, a much harder and more refractory type was introduced at the beginning of the next century, and (apart from the recent partial introduction of a milder type for special purposes) this type has remained in use to the present day. The lime in Brongniart’s new paste was reduced to 5 per cent., while the amount of kaolin (65 per cent.) is probably greater than in any other porcelain. There has been a reaction lately at Sèvres against this refractory ware, but the old formulas are still employed for the porcelain made for practical domestic use. When, however, brilliancy of effect and artistic decoration are aimed at, a completely new type both of paste and glaze has been in use since the year 1880, and concomitantly with the imitation of the Chinese monochrome wares, an attempt has been made to follow as closely as possible the pastes and glazes of the Chinese. M. Vogt, the present technical director at Sèvres, who has had so much to do with these changes, gives the following formula for the composition of the new porcelain: kaolin 38 per cent., felspar 38 per cent., quartz 24 per cent. The lime, it will be seen, has been completely eliminated from the paste; on the other hand, the glaze contains as much as 33 per cent. of the _Craie de Bougival_.