of Mineral Waters. 227 



If the quantity of muriate of magnesia be considerable, greater 

 accuracy is ensured by converting it into sulphate, which is 

 done by placing it in a capsule of platinum, pouring upon it 

 sulphuric acid, evaporating to dryness, and heating the dry mass 

 to dull redness. One hundred grains of this dry sulphate of 

 magnesia indicate 94 of muriate of magnesia ; hence the water 

 under examination would have given 5.35 grains = 5 grains of 

 muriate. 



If the alcoholic solution contain muriate of lime, that earth 

 must be previously separated by oxalic acid; and 100 parts of 

 oxalate of lime are equivalent to 85 of dry muriate of lime. 



16. The aqueous solution of the residue (C 11) being divided 

 into two portions, let us suppose the portion (a 11) to afford 8.5 

 of chloride of silver, which indicates of sea salt 3.5 grains =: 7 

 grains in the pint. 



17. Let us assume, that the precipitate of sulphate of baryta 

 {b 11.) weighs 15 grains, indicating of 



Sulphuric acid 5.1 grains. 



The process directed in 1 1 furnishes of 



Sulphate of magnesia 3.75 grains, 



which contain 2.5 grains of sulphuric acid, and which deducted 

 from 5.1 grains leave 2.6 grains, which are adequate to the for- 

 mation of 



Sulphate of soda ..,,.. 4.65 grains. 

 So that the pint (the water having been divided into two equal 

 portions) would contain of 



Sulphate of magnesia 3.75 x 2 = 7.5 grains. 

 Sulphate of soda .... 4.65 x 2 = 9.3 grains. 



18. The addition of oxalate of ammonia, or oxalic acid, to 

 a pint of the boiled water (12) furnishes a precipitate of 4.7 

 grains of oxalate of lime, indicating of 



Sulphate of lime 5 grains. 



19. To give a general view, therefore, of the components of 

 the mineral water which has thus been examined, we should 

 place them as follows : — 



