Mr. J. Brown on the Products of the Soda Manufacture. 23 



6. Magnesia. — This was precipitated by ammonia and phos- 

 phate of soda. 



Ball soda. 2MgO, P^ O5. MgO per cent. 



100 gave . 0-980 0-350 



7. Silica and sand. — The soda ball was dissolved in muriatic 

 acid and the solution evaporated to dryness. The residue 

 was then digested with strong muriatic acid, and the insoluble 

 matter separated by filtration. 



Ball soda. Silica and sand. Silica and sand per cent. 

 56-00 gave . 4*30 7-679 



The silica was separated from the sand by strong caustic 

 potash. 



Ball soda. Sand. Sand per cent. Silica per cent. 



56-00 gave 2-40 4-285 3-394 



8. Iron and alumina. — A portion of the soda ball was dis- 

 solved in muriatic acid, and after separating the insoluble 

 matter, the iron and alumina were precipitated by caustic am- 

 monia. 



Ball soda. AI2O3 & Fcj O3. AI2O3 & Fcj O3 per cent. 

 61-20 gave 3-45 5*637 



19-53 ... 1-15 5-888 



29-10 ... 1-45 4-982 



Average 5*502 



The peroxide of iron was separated from the alumina by 

 caustic potash. 



Ball soda. Fe2 O3. Fe2 O3 per cent. Fe per cent. AI2O3 per cent. 



61-20 gave 2-94 4-804 3-363 0-833 



29-10 ... 1-20 4-123 2-886 0-859 



Average 3-129 0-846 



9. Lime. — From the solution filtered from the alumina and 

 iron, the lime was precipitated by oxalate of ammonia. 



Bali soda. CaO, COj. CaO. CaO per cent. 



61-20 gave 33-00 18-480 30-194 



29-10 ... 15-50 8-680 29-828 



21-80 ... 12-05 6-748 30-954 



Average 30-325 



10. Carbonic acid. — By the addition of muriatic acid to 

 the ball soda, sulphuretted hydrogen and carbonic acid gases 

 were evolved, which were passed through a strong solution of 

 caustic barytes. The precipitated carbonate of barytes was 

 filtered as rapidly as possible, care being taken to keep it 

 covered with a plate of glass during the process. 



