50 M. S. D. Westropp on 



the West Indies might now prove happy hunting grounds for old 

 Irish cut glass. 



At the present day it is often very difficult to say whether a 

 particular piece of glass is of Irish or English make ; and it is 

 still more difficult to differentiate between the products of the 

 various Irish factories, unless pieces bear marks indicating the 

 place of manufacture. There are some who profess to be able to 

 distinguish definitely between the glass of the different Irish 

 factories, but on what grounds it is difficult to ascertain. There 

 does not appear to be any hard and fast rule to go by with regard 

 to colour, shape or cutting. Some of the Waterford glass is fairly 

 white, while some Cork glass has a dark tint, but here again there 

 is no definite rule to go by. 



A good deal of the old cut glass now found in Ireland has a 

 decided bluish tint, which is commonly said to indicate that it was 

 made in Waterford, though on what authority no one seems to 

 know. The bluish tint is simply caused by impure oxide of lead 

 being used in the manufacture, and as this might have occurred 

 in any pot of metal, glass with this bluish tint may have been 

 made in any of the Irish, or even in the English, factories. 



The following is an analysis, kindly made by the Royal 

 Dublin Society, of a piece of glass having this bluish tint : — 

 Lead Oxide ... .. ... 3656 



Potash ... .. ... ... 8-48 



Soda ... ... ... ... 3'o8 



Silica, including traces of other oxides ... 51*88 



There was no trace of cobalt, to which some attribute the 

 blue tint. 



The metal of Irish and English flint glass was made from 

 practically the same materials, the sand being obtained chiefly 

 from the Isle of Wight. Thomas Wallace in his Essay on the 

 Manufactures of It e/a?id, Dublin, 1798, states that "The principal 

 materials connected with glass making are imported from England, 

 though we are able to undersell the British manufacturers ; the 



