186 J. M. Ordway on Waterglass. 
the phenomenon of fusion too, though almost all bodies liquefy 
at a temperature which is invariable and exa 
and as 
the several observers have examined crystals obtained by unlike: 
Yorke” fused 23 parts of sand with 54 parts of dry carbon- 4 
ate of soda, dissolved the resulting mass in water, and exposed 
the solution to slow evaporation in vacuo, over sulphuric acid. 
—— ound these crystals to part with all their water, except 
@ traction of one per cent, by exposure to a heat of 149°C. 
usmann "says that in the purification of rough a 
mother liquor has often yielded him, in large quantity (manch- 
i\mmon 
aoe crystals, by dissolving silica in soda lye. They fused at 
® Pogg. Ann, xliii, 1 ss ; ms 
= po3 alee jou e Phil, Trans., 1857, p. 533. Se 
