108 COLOURS OBTAINED FROM METALLIC OXfDfc'SV 



fire without being volatilized or difcoloured. Their folvem 

 is thefeld fpar. As they' incorporate with the glaze they ne- 

 ver crack, and are more brilliant. 



The third receptacle of metallic verifiable colours is glafs 

 without lead. 

 Art of painting The application of thefe colours conftitutes the art of paint- 

 on glafs, m g on g| a f g . an art Jnuc j 1 p ra ftif e a in former ages, but which 

 is fuppofed to be loft, becaufeout of fafhion. It however too 

 immediately depends on the art of painting on enamel and 

 It not loft. porcelain to be intirely loft. Defcriptions of the proceftes may 



alio be found in many different works. 

 Books in which A book intitled, L'Originede V Art dc^a Peinture fur Verre, 

 Ori inah^' P ub,i(hed at Paris in the year 1693, and Le Traite de V Art de 

 la Verrerie, by Neri and Kmickel, feem to be the fir ft works 

 containing complete defcriptions of this art. Thofe publithed 

 Leviel's work isfince, even the great work of Leviel, which conftitutes part of 

 tkHi/ C ° mpi a " ^ es ^ rts et Metiers of the academy, and of the Encyclopedic 

 Methodifjue, are only compilations from the two former works. 

 The others af- It is fomewhat remarkable, that if we follow the procefles 

 inftruaion? 01 ' exa ^ty as lrie y are defcribed in thefe works, as I have done 

 with fome of them, the colours of which they pretend to give 

 (he receipt would never be fabricated. They only ferve to 

 mew an able practician the method, and leave it to him to 

 correct or make additions. This was found to be the cafe by- 

 Citizen Meraud, who was engaged to prepare them for the 

 manufactory of SeVres. He was obliged to make the colours 

 for painting on glafs rather from his own experience, than from 

 the inftruclions in the works I have juft mentioned. 

 The colours for The limits of a memoir will not permit me to enter intohif- 

 g a * are near y { or j ca j details on the art of painting on glafs ; its hiftory is 

 enamel 5 but given at length in Leviel's work; the materials and fluxes 

 fome of them are wn i cn cn ter into the compofition of the colours for painting on 

 dull for want of . _ , , , r , r ■> , f • 



theopake glais, are in general the lame as thole applied to porcelain. 



ground. They vary only in their proportions ; but a great number of 



the colours ufed for enamel and porcelain cannot be applied 

 to glafs ; many of them when feen by tranfmitted light intirely 

 change their afpect, and exhibit an obfeure tint which can be 

 of no ufe when deprived of the white ground which throws 

 them out. We mall point ouKthefe when we treat of the 

 colours in particular. Thofe colours which can be ufed on 



this 



