2G4 Mr. Brown on the Products of the Soda Manufacture. 



The quantity of magnesia was ascertained by precipitation by ammonia 

 and phosphate of soda, the lime having been previously separated : — 



2 Mg O P O a Mg O Mg per 1000 grs. 



2000 grains of salt gave, ... 465 1*660 830 



The carbonate of lime remained as insoluble matter when the salt was 



digested in water, and was separated by filtration: — 



Ca O C0 2 

 Ca O C0 2 per 1000 grs. 



2000 grains of salt gave, 3000 1*50 



By estimating the amount lost by drying the salt at 212°, the quantity 



of water was ascertained : — 



Water, per 1000 grs. 



330-2 grains of salt lost, 1796 54-373 



In order to estimate the quantity of iodide of potassium and bromide 

 of magnesium, 1 J lbs. of salt were put into a funnel, the lower end of 

 which was closed with filtering paper. The salt was then repeatedly 

 washed with boiling water. The iodide and bromide were thus taken 

 up by the water along with a large quantity of common salt. This 

 solution was evaporated to dryness, and the residue digested in alcohol, 

 which dissolved the iodide and bromide, along with a little of the salt, 

 leaving, however, the greater part of it, which was afterwards separated 

 by filtration. The filtered solution was again evaporated to dryness, 

 and the residue digested in water. Chloride of palladium was then added, 

 but no precipitation of iodide of palladium took place. The palladium 

 was precipitated by sulphuretted hydrogen; and the sulphuret of palladium 

 thus formed separated by filtration. Upon testing the filtered solution 

 with ammonia and nitrate of silver, no precipitate was obtained. Had 

 bromine been present, it would have been precipitated in combination 

 with the silver, bromide of silver being insoluble in caustic ammonia. It 

 is therefore evident, that the common salt, manufactured as previously 

 mentioned, does not contain iodine or bromine; although it is highly 

 probable that these bodies are present in small quantity in rock salt, and 

 we might therefore be able to detect them in the brine from which the 

 magnesia salts are manufactured. 



Upon treating the salt with bichloride of platinum, a slight precipitate 

 of potash bichloride of platinum was obtained : — 



Sulphuric 

 Magnesia. Lime. Acid. 



Chloride of sodium, 931*615 — — — 



Chloride of potassium, trace, — — — 



Chloride of magnesium, 1*066 0*381 — — 



Sulphate of lime, 10098 — 4*158 5940 



Sulphate of magnesia, 1*348 0*449 — 0*899 



Carbonate of lime, 1*500 — — — 



Water, 54*373 — — — 



1000000 0*830 4*158 6*839 



