Letters^ of Mr. Brongniart, with remarks, 21*? 



undergo, in arriving at the condition of Porcelain. The cat- 

 alogue which is in the box will give you an idea of the order 

 of these processes." 



Mr. Brongniart, as is well known, is director of the great 

 Nationalmanufactory of Porcelain, at Sevres, near Paris, and 

 therefore, authentic specimens, of this kind received from him, 

 must be regarded as particularly valuable. A mere translation 

 of the catalogue, (which is however, full and detailed) without 

 an exhibition of the specimens, would probably not be very 

 useful. We will content ourselves with saying, that the 

 specimens are very instructive, and conduct the observer, 

 gradually, from the crude natural clay, sand, white feldspars, 

 decomposed graphic granite, &c. through the regular series 

 of changes, till we arrive at the finished vessel, possessing 

 the whiteness, lustre, infusibility,* imperviousness to fluids, 

 anddehcate translucence, which are among the qualities that 

 characterize one of the most perfect and beautiful produc- 

 tions of human skill. The tablets that illustrate the paint- 

 ing of the porcelain, are particularly elegant, and embrace 

 most of the colours that are applied for the purposes of dec- 

 oration. 



Gold andplatina are applied in the metallic state, and bur- 

 nished so as to produce the proper lustre and colour of those 

 metals. But, in most instances, the metallic oxids, applied 

 by the pencil, are incorporated by heat, and actually form 

 part of the substance of the porcelain, so that the colours 

 cannot be discharged, and are scarcely liable to fade even 

 by the action of light. Thus, cobalt gives an intense blue- 

 chrome — a grass-green, and gold-rich purples and violets. 

 The principle of their application is the same with that of 

 glass and enamel staining, and the superb painted glass win- 

 dows in the Gothic Cathedrals in Europe evince both the early 

 perfection of the art, and the endurance of these colours, from 

 century to century, iri unfaded splendor.f These facts are 

 finely illustrated by Mr. Brongniart's specimens, which will 

 be freely submitted to the view of those whom either curi- 

 osity or interest may allure to this subjects Before return- 



* By furnace heats. 



t It is almost unnecessary to remark, that the colours of the animal and 

 vegetable kingdom which form our common dyes are inapplicable in 

 cases where they must be burnt it, as it is termed ; they would of course be 

 destroyed. 



Vol. Ill No. 2. 28 



