278 A GENERAL FORMULA FOR THE 



ved. To remove the former more completely, when the solu- 

 tion is poured off, add to the residue about twice its weight of 

 the same alcohol, and allow them to stand for some hours, agi- 

 tating frequently. And when this liquor is poured off, wash 

 the undissolved matter with a small portion of alcohol, which 

 add to the former liquors. 



Although muriate of soda by itself is insoluble, or nearly so, 

 in alcohol of this strength, yet when submitted to its action 

 along with muriate of lime or of magnesia, a little of it is dis- 

 solved. To guard against error from this, therefore, evaporate 

 or distil the alcoholic solution to dryness, and submit the dry 

 mass, again, to the action of alcohol in smaller quantity than 

 before ; any muriate of soda which had been dissolved will 

 now remain undissolved, and may be added to the other por- 

 tion ; or at least any quantity of it dissolved must be extreme- 

 ly minute. A slight trace of muriate of lime or of magnesia 

 may adhere to the muriate of soda, but when a sufficient quan- 

 tity of alcohol has been employed, the quantity is scarcely ap- 

 preciable ; and the trivial errors from these two circumstances 

 counteract each other, and so far serve to give the result more 

 nearly accurate. 



Evaporate the alcohol of the solution, or draw it off bv dis- 

 tillation. To the solid matter add sulphuric acid, so as to ex- 

 pel the whole muriatic acid ; and expose the residue to a heat 

 approaching to redness, to remove any excess of sulphuric acid. 

 By lixiviation with a small portion of water, the sulphate of 

 magnesia will be dissolved, the sulphate oflime remaining un- 

 dissolved, and the quantities of each, after exposure to a low 

 red heat, will give the proportions of lime and magnesia. The 

 quantity of soda will be found from the weight of the muriate 

 of soda heated to redness ; and the quantities of the acids will 

 be determined in the same manner as in the general formula. 



This 



