ggO ANALYSIS OF BRITISH AND FOREIGN SALT* 



(F. a.) If in any mixture of salts, free from the earthy 

 muriates, *e are certain that no other sulphates exist beside 

 those of lime and magnesia, their estimation becomes ex- 

 tremely simple. Decompose two equal quantities of the 

 salt in question, the one by muriate of barytes, the other 

 by oxalate of potash. From the weight of the latter pre- 

 cipitate we may calculate the quantity of sulphate of lime. 

 Suppose, for example, the oxalate of lime (as was actually 

 the case with the precipitate from 1000 grains of Lyming- 

 ton salt,) to weigh 12 grains: these denote 15 of sulphate of 

 lime, dried at 160° Fahrenheit ; winch quantity, if decom- 

 posed, would give 20| of sulphate of barytes. 1 lie latter 

 number (20f), subtracted from the weight of sulphate of 

 barytes actually obtained (say 00), gives 39} grains for the 

 sulphate of barytes resulting from the decomposition of the 

 sulphate of magnesia. The quantity of the latter salt, it 

 will be fgund, therefore, by applying the rule already given 

 (1). <?.), must be 35 g -rains, 



(F. b.) The same object may be accomplished by decom- 

 posing two equal quantities, the one by oxalate of potash, 

 the other by the compound solution (D. c.) From the 

 weights of the precipitates it is easy to calculate, from how 

 much of the calcareous and magnesian sulphates they have 

 resulted. 

 Separation of (G.) When the salt left by alcohol was known to contain 

 alkalme sui- muriate of soda, and sulphate of magnesia, but no sulphate 

 V * of lime, ■ -,e presence of alkaline sulphates was investigated 



in the following manner. The salt was dissolved in water, 

 and t&e solution was divided into two equal portions. To 

 the o>ie muriate of barytes was added, and to the other, the 

 compound precipitant of carbonate of ammonia, and phos- 

 phate of scda. If the sulphate of barytes, thus produced, 

 bore to the ammoniaco-magnesian phosphate the proportion 

 of 112 to 90, it was concluded, that no other sulphate had 

 been decomposed, but that with base of magnesia. 



(H.) At one time, 1 expected to have ascertained the quan- 

 tity of sulphate of soda, in an artificial mixture of that salt 

 with sulphate of magnesia and muriate of soda, by the fol- 

 lowing formula. To a solution of the three salts, heated to 

 9 boiling temperature, I added subcarbonate of ammonia, 



which 



