440 REPORT OF NATIONAL MUSEUM, 1888 



M. Salvetat wrote in 1855, aud be considered their production in China 

 as due rather to accident than design. The justice of this view is, 

 however, perhaps open to question, for the Chinese appear to have 

 at least an empirical knowledge of the conditions necessary to produce 

 these colors, though they are unable in all cases to insure those con- 

 ditions. The, fond laqne or feuille morte is obtained by the use of oxide 

 of iron, the amount of that metal aud the nature of the gas surrounding 

 the vessel in the kiln determining the tone of the color from a light 

 shade to one resembling bronze, and warmth of color being obtained by 

 an oxidizing atmosphere. Black grounds are produced in a variety of 

 ways, either by the thickness of the colored glaze, or by laying several 

 shades of different colors one on the other, or, again, by laying a blue 

 glaze on a brown laque, or vice versa. 



M. Salvetat states that among the colors for the ground employed in 

 China some are evidently applied upon the biscuit, i. e., porcelain 

 already fired at a high temperature. These are violet, turquoise blue, 

 yellow^ and green, all containing a pretty large proportion of oxide of 

 lead ; and, vitrifying as they do at a medium temperature, hold a posi- 

 tion half way between the two main categories and may be therefore 

 termed colors du demi-grand feu. Nothing approaching these colors, he 

 says, is produced in Europe. To do so, however, would not be difficult, 

 the green and turquoise blue owing their colors to copper, the yellow 

 to lead and antimony, and the violet to an oxide of manganese contain- 

 ing but little cobalt. 



Colors de moufle. — In Europe these colors are obtained by mixing one 

 oxide or several metallic oxides together with a vitreous flux, the 

 composition of which varies with the nature of the color to be devel- 

 oped. That most generally used is termed " the flux for grays." It 

 serves not only for grays, however, but also for blacks, reds, blues, 

 and yellows, and is composed of six parts of minium, two parts of sili- 

 cious sand, and one part of melted borax. The colors are obtained by 

 mixing by weight one part of metallic oxide with three jjarts of the 

 flux, so that the composition may be expressed thus : 



Silica 16.7 



Oxide of lead 50.0 



Borax, 8.3 



Coloring oxides 25.0 



100. 



In cases where, as with oxide of cobalt, the colors are produced by 

 mixture with the flux and ought to have the required shade when 

 applied, the metallic oxides are melted with the flux prior to use; in 

 those, however, where the desired color«is that inherent in the oxide, 

 the tone of which would be changed by a double exposure to fire, as is 

 the case with reds derived from peroxide of iron, the union with the 

 flux by melting is dispensed with. The colors so made suffice to permit 

 the reproduction on porcelain of oil paintings ; but it is essential that 



