On the Manufacture of Salt in India. 255 



The mother liquor, or bittern of the Lymington salt works, 

 specific gravity 1280, contained, according to the analysis of 

 Dr. Henry,* 



Muriate of magnesia, 640 



Sulphate of magnesia, 260 



Muriate of soda, 100 



Total, 1,000 



As no muriate of lime was found in the bitterns examined 

 by Dr. Henry, this chemist is of opinion, that the lime in 

 other bitterns is derived from the soil from which the evapo- 

 ration is conducted ; and to shew how the different ingredi- 

 ents vary in proportion, according to the method adopted, the 

 following results of analysis of Scotch bittern supplied to Dr. 

 Henry by Dr. Thomson, may be stated : — 



Muriate of magnesia, . 874 



Sulphate of magnesia, ... 70 



Muriate of soda, ... ... ... 56 



Total, ... ... ... 1,000 



The following are the results of analysis of a specimen 



of bittern from the Calcutta Salt Agency, of a clear yellow 

 colour, specific gravity 1280 : — 



Muriate of lime, ... 510 



Muriate of soda, 264 



Sulphate of soda, 173 



Muriate of magnesia, ... ... ... 48 



Vegetable matter, 5 



Total, ... ... ... 1,000 



* The analysis of sea water, says Dr. Henry, by Bergman, erroneously 

 excludes sulphate of magnesia from its composition, and his results have 

 led to the opinion that to manufacture this salt on a large scale, requires 

 the addition of sulphuric acid, or some sulphate to the bitter liquor. — 

 Philosophical Transactions for 1810. 



