Intelligence and Miscellaneons Articles. 1 47 



■which is to be treated with sether, wliich dissolves one portion and 

 leaves another which is insoluble : this last is glycerine, and the 

 solution contains the aethers of the fatty acids of the castor-oil. — 

 Journ. de Pharm. et de Ch., Decembre 1846. 



ON THE COMPOSITION OF BOHEMIAN GLASS. 



According to M. Peligot, the composition of the white Bohemian 

 glass varies but very little in the different manufactories of that 

 country. He has analysed various specimens which were perfectly 

 pure and colourless, and they all yielded very nearly the same results. 

 Their composition was found to be as follows : — 



Silica 76 



Potash 15 



Lime 8 



Alumina 1 



100 

 The composition of the verre-agate, or verre de pdte de riz of 

 Bohemia is remarkable ; it is a simple silicate of potash, the semi- 

 opacity of which is derived from imperfect vitrification, which has 

 left grains of quartz, not fused, interposed in the mass. It contains, 

 according to M. Peligot's analysis, — 



Silica. r 80-9 



Potash 17-6 



Lime 0-7 



Alumina and a trace of iron .... 0*8 



100-0 

 This glass does not attract moisture from the air; when long 

 boiled in water it is not acted upon. It differs from the soluble 

 glass of Fuchs in containing about 10 per cent, more silica. 

 A specimen of Venetian artificial avanturine yielded — 



Silica 67-7 



Lime 8-9 



Peroxide of iron 3'5 



Oxide of tin 2-3 



Oxide of lead 1*1 



Metallic copper 3'9 



Potash 55 



Soda 7-1 



1000 

 M, Peligot found that a specimen of verre d, places souflees consisted 

 of— 



Silica 67-7 



Potash 21-0 



Lime 99 



Alumina r4 



100-0 

 Journ. de Pharm. et de Ch., Novembre 1846. 



