Mr. Brown on the Products of the Soda Manufacture. M 



2 parts dry sulphate of soda. 



3 — carbonate of lime. 

 1 — ground charcoal. 



These were intimately mixed, and introduced into a reverberatory furnace, 

 whore a strong heat was applied. After this had been continued for 

 about mi hour, the fused muss wis raked out of the furnace and allowed 

 to solidify. When this cooled, it was broken up and exposed to the action 

 of moist air, which caused it to crumble down. In this way the caustic 

 soda was converted into carbonate of soda, the carbonic acid being derived 

 from the atmosphere. After being ground, it was ready for use. 



The soda process, as at present carried on, will be best considered under 

 the four following heads : — 



I. The production of sulphate of soda from salt and sulphuric acid. 



II. The conversion of sulphate of soda into crude carbonate of soda, or 

 British barilla. 



III. The soda ash process. 



IV. The carbonate of soda process. 



The first stage which thus comes under our consideration is — 



L The Decomposition of common Salt by Sulphuric Acid, causing the 

 formation of Sulphate of Soda and Muriatic Acid 



The salt used in this process is obtained from the brine springs of 

 Cheshire which exist abundantly in the new red sandstone of that county. 

 The solution is evaporated till it reaches a certain strength, when all the 

 salt precipitates. It is then raked out into wicker baskets and allowed 

 to drain. The mother liquor is used for the manufacture of the salts of 

 magnesia. The salt thus obtained, contains, as might be expected, 

 numerous impurities, the principal of which are lime, sulphuric acid, and 

 magnesia. 



To estimate the lime, a portion of the salt was dissolved in water, and 

 alter separating the insoluble matter by filtration, the lime was precipitated 

 by ammonia and oxalic acid, a largo quantity of muriate of ammonia 

 being added to retain the magnesia in solution. 



CaO 

 Ca O CO a Ca O per 1000 grs. 



2000 grains of salt gave,. ..15-10 8*456 4-228 



2000 — — .. .14-00 8-176 4-088 



Average, 4158 



The sulphuric acid was precipitated by the addition of nitric acid and 

 nitrate of barytes: — 



SO, 

 Ba O S0 3 S0 3 per 1000 grs. 



•^<hi0 grains of salt gave,... 39-85 13738 6'869 



■iOOO — — ... 39-50 13-620 6-810 



Average, 6*839 



