Mr. J. Brown on the Products of the Soda Manufacture. 25 



It will be seen that in the above analysis I consider almost 

 all the soda to be united with carbonic acid, there being very 

 little caustic soda. Unger and others who have examined the 

 soda balls, fall into the error of supposing a large quantity of 

 the alkali to exist as hydrate, and also of always finding car- 

 bonate of lime; but if a portion of the ball soda be digested 

 in alcohol, and the alcoholic liquor carefully examined, it will 

 be found that it holds in solution a very small quantity of 

 alkali, which I consider to be as sulphuret. If, on the con- 

 trary, the soda balls contained caustic soda, it would be im- 

 mediately dissolved by the alcohol, and we should obtain a 

 strongly alkaline solution. This, however, is not the case. 

 But if the ball soda be digested in water, the liquid will be 

 found to contain a large quantity of caustic soda, which, how- 

 ever, can easily be accounted for in the following way. There 

 exists in the ball soda a large quantity of caustic lime ; and 

 whenever water is added to it a decomposition takes place, 

 carbonate of soda and caustic lime becoming carbonate of lime 

 and caustic soda, — 



NaO, C02+CaO = CaO, CO^+NaO. 



Some analysts have also found water of combination in ball 

 soda, that is, water united to soda or lime. But this is im- 

 possible, for where does the water come from ? The materials 

 contain none. A small quantity of water is certainly formed 

 in the combustion of coal, but this is not sufficient to account 

 for it. The method of analysis pursued in the determination 

 of the amount of water combined with soda or lime was, I 

 think, very incorrect : it was to burn the ball soda with chro- 

 mate of lead, and determine the weight of the water given off. 



