Mb. Brown on the Products of the Soda Manufacture. 281 



As it contains 10 atoms of water of crystallisation, its formula is 

 NaO C0 3 +10 HO ; and the per centage calculated from this formula 

 gives,— 



Carbonate of soda, 37500 



Water, 62*500 



100-000 



By driving off the water from these crystals by heat, a very pure car- 

 bonate of soda is obtained, which is used by the glass makers. It 

 yielded, on analysis, — 



i. n. 



Carbonate of soda, 98*120 97*984 



Sulphate of soda, 1*076 1-124 



Chloride of sodium, 0*742 0*563 



99*938 99-671 



