646 



GLASS 



In the following table are also given the analyses of a certain number of Bohemian 

 glasses, which will indicate their composition with precision, and show how uncertain 

 their composition is : 



No. 1. Bohemian glass from Neufeld (M. Grus). 



No. 2. A fine table glass from Neuwelt (M. Berthior) ; it is exceedingly beautiful, 

 and is prepared, according to M. Perdonnet, with a mixture of 100 quartz, 50 caustic 

 lime, 75 carbonate of potash, and a very small quantity of nitre, arsenious acid, and 

 oxide of manganese. 



No. 3. Old Bohemian glass (M. Dumas). 



No. 4. Crown-glass of German manufacture (M. Dumas). 



No. 5. Glass for mirrors (M. Dumas). 



No. 6. Another glass for mirrors (M. Dumas). 



No. 7. White table glass, from Siberberg near Gratzen. 



No. 8. Mirror- glass from New- Hurken thai, for the manufacture of cast mirrors. 



Poligot gives the analysis of Venetian aventurine as follows : 



Silica 

 Potash 

 Lime 

 Soda 



677 

 5-5 

 8-9 

 7-1 



Oxide of Tin 

 Oxide of Lead 

 Metallic Copper 

 Oxide of Iron 



. 2-3 

 . 1-1 

 . 3-9 

 . 3-5 

 See AVENTURINE. 



The following analyses of different varieties of Continental glass aro instructive : 



No. 1. is a very beautiful white wine-glass of Nouwolt in Bohemia. 

 No. 2. Glass tubes, much more fusible than common wine-glasses. 

 No. 3. Crown-glass of Bohemia. 

 No. 4. Plask-glass of St. Etionne, for which some heavy spar is used. 



