Art of Painting in Enamel. 449 



this in view tlirouivhout the experiments which I have made 

 for the purpose of obtaining a set of enamel colours which 

 should combine with the required richness of tone and bril- 

 liancy of tint, the property of remaining unchanged during the 

 numerous exposures to the heat of the furnace to which a 

 painting in enamel is necessarily subjected. Of the necessity 

 for simplification, and also of the extent to which it is capable 

 of being carried, take the following example. 



In vol. xxxv. of the Transactions of the Society for the En- 

 couragement of Arts, &c. p. 49, it is stated, that " Twenty 

 guineas were this session (1817) voted to Mr. R. Wynn for 

 receipts for enamel colours and for staining and gilding on 

 glass." One of these receipts, for green, is given thus, at p. 60 : 

 *' A frit for transparent greens. 



" Take flint powder 3 ^ 



Flux No. 2 (p. 55) 3 I 



Green pot-metal glass H L 



Red-lead 7i f 



Raw borax 2^ ■ 



Green oxide of copper 1 ^ J 



" Melt them in a crucible, pour out the mass, and pound it 

 in an earthen mortar. 



Take of the green frit 3 



Of yellow enamel colour (p. 56) 1^ 



" If too soft add Naples yellow." 



Now in order to see the whole complexity of this receipt let 

 us make an analysis of its contents ; and then contrast it with 

 the simplicity which experience shows to be attainable. 



Frit. 

 Flint powder 3 



®* fp'iJ^^ r Silica . . . . l 1 



b I White arsenic 1 f 



S LNitre IJ 



Green f Silica 'j 



pot- J Alkali I ,, 



metal \ Oxide of lead, 

 glass. [, Oxide of copper J 



Red lead 7^ ^ "o 



Raw borax 2| j 13 ^ 



Green ox, of copper M J C! 



O 



Of this when melted take 3 



"Z fRed-lead 81 



Oxide of antimony 1 l 1 ") 



I «* I White oxide of tin 



•^=, ^ fRed-lead 91") | 



---^ 6 I Borax 5| 1 >H 



'^ <j?v . r Silica .... 1 >H 



I t^^^^^-lOx.oflead 

 Here it may be observed that silica is introduced in four 



* This receipt for " yellow enamel colour" is given by Mr. Wynn at p. 56 

 of the volume referred to. 



Third Series. Vol. 10. No. 63. June\S%l. 3 M 



