PROCEEDINGS OF SECTION B. 



329 



Manganese. — " A" solution (amnionia precipitation of iron, &c.). 

 The combined filtrates from the alumina-iron precipitation were eva- 

 porated down and filtered, the small amount of AI2O3 recovered being 

 added to the main precipitate. The solution was made acid with HCl 

 boiled, ammonia added, and bromine water. The excess of this was 

 then boiled off, and th-? solution digested for two hours on the hot 

 plate. The manganese was filtered and weighed. 



" B " solution (basic acetate separation). In these duplicates 

 Hillebrand's method for manganese was closely followed, separating 

 by sulphuretted hydrogen in ammoniacal solution, and finally pre- 

 cipitating vrith. sodium carbonate. 



Table IV. 



Treatment. 



MngO^. 



A (Ammonia precipitation of iron, &c.). 



Manganese by bromine 



B Acetate precipitation of iron. &c. . . . 



Manganese by soda carb 



1 .0016 



2 .0016 



1 .0019 



2 .0016 



The complete analyses of this sample were made for the purpose 

 of comparison in methods. The final results were as follows (]VIr. Alan 

 Hall) :— 



Table V. 



* Through an accident in reduction, the figures for total iron in the B analyses 

 were unreliable, so in this case the figures from A were taken : otherwise the results 

 are cjuite independent. Three determinations were made of alkalies, the results as 

 shown above being excellent. 



