194 PHYSIOLOGICAL REMAINS. 



chalcedon, being a stuff between a porcelane and 

 a glass. 



For the first, it is good first to know exactly the 

 several materials whereof the glass in use is made ; 

 window-glass, Normandy and Burgundy, ale-house 

 glass, English drinking-glass : and then thereupon 

 to consider what the reason is of the coarseness or 

 clearness ; and from thence to rise to a consideration 

 how to make some additaments to the coarser ma 

 terials, to raise them to the whiteness and crystalline 

 splendor of the finest. 



For the second, we see pebbles, and some other 

 stones, will cut as fine as crystal, which if they will 

 melt, may be a mixture for glass, and may make it 

 more tough and more crystalline. Besides, we see 

 metals will vitrify ; and perhaps some portion of 

 the glass of metal vitrified, mixed in the pot of 

 ordinary glass-metal, will make the whole mass 

 more tough. 



For the third, it were good to have of coloured 

 window-glass, such as is coloured in the pot, and not 

 by colours 



It is to be known of what stuff galletyle is made, 

 and how the colours in it are varied ; and thereupon 

 to consider how to make the mixture of glass-metal 

 and them, whereof I have seen the example. 



Inquire what be the stones that do easiltest melt. 

 Of them take half a pound, and of iron a pound and 

 half, and an ounce of brimstone, and see whether 

 they will incorporate, being whole, with a strong 

 fire. If not, try the same quantities calcined : and 



