2/2 Receipts for Enamel Colours, 



The latter ingredient is prepared by dissolving silver in aquS' 

 fortis, and precipitating it with common salt. 



Grind in water for use ; if too purple, add more muriate of 

 silver. 



Opake White. 



Hartshorn shavings burnt in a crucible, in a charcoal fire, till 

 perfectly wkite, . . . . . . . , . . 1 



Fhix, No. 1 L 



Grind in water for use. 



Venetian white cake enamel . . 1 

 Flux, No. S I 



Grind in water, then calcine them together in a muffle. 



Fkix, No. 2, pounded and washed, then dried and calcined in 

 a muffle. 



It would not be difficult to exhibit a multitude of specimens 

 of different tints, and fill a volume with descriptions of them, 

 by combining these original enamel colours in various propor- 

 tions : this, however, may safely be left to the taste and expe- 

 rience of the artist. My object has been to avoid every thing 

 superfluous, and at the same time to explain the processes 

 adapted to immediate practice in terms not liable to be mistaken. 



Sir, — When I had the honour of explaining my Treatise on 

 Enamel Colours to the gentlemen forming the Committee of 

 Chemistry, I was requested by them to produce the method of 

 staitii/ig glass, with a view of adding it as a second part to the 

 Treatise on Enamel Colours. 



I have inserted the most valuable information which I possess, 

 on this subject in tlie paper that accompanies this letter, and 

 request that you will present it in my name to the Society of 

 Arts. I am, sir, 



Your most obedient humble servant. 

 No. 3, Tnylors-Buildisgs, May 6, 1817- RoBERT WyNN. 



To A. Aikin, Esq. Sec. 



The Art of staining Glass. 



In coloured glass, the whole body of the material is tinged 

 throughout by means of some colouring ingredient uniformly dif- 

 fused through, or dissolved in, the substance of the glass. 



In enameling, the colours, being ground up with an easily vi- 

 trifiable flux, are laid on the surface of metal, or porcelain, or 

 glass, and are then exposed to such a degree of heat as shall just 

 melt the enamel, and then fix it on the surface of the substance 

 on which it has been applied. 



In staining glass, the colouring ingredients are mixed with 



water,' 



