COMMON OR TABLE SALT 



SALT 



SODIUM CHLORIDE: 



Supply 



Rajputana (Journ. Ind. Art Indust., 1901, ix., No. 73). He tells us that 

 the salt industry of Rajputana produces about 200,000 tons a year and 

 meets the requirements of 59 millions of people. The Sambhar Lake, 

 it is believed, has been worked for salt for the past 1,400 years. It is 

 about 20 miles in length, the breadth varying from 2 to 7 miles, and it 

 covers an area of 90 square miles. The surrounding country is sandy 

 and sterile, with the great Indian desert to the westward. The density 

 of the lake brine varies with the annual accumulation of water. In years 

 of normal rainfall it is about 3 Beaume (the density of sea-water), but 

 when very full is considerably less, and during years of drought it may 

 be as high as 10 Beaume. 



The lake was taken over by the Indian Government in 1871, and since 

 that date has yielded 4 million tons of salt. It lies within the boundaries 

 of the Native States of Jaipur and Jodhpur. Holland remarks that 

 " the Sambhar Lake is a silt-filled depression in the Aravalli schists and 

 gneisses, in which a body of mud and sand with Jcankar and gypsum (some 

 75 feet thick in what appears to be about the centre of the depression) 

 includes from 2 to 12 per cent, of sodic chloride, with smaller quantities 

 of sodic sulphate, sodic carbonate and potassic sulphate. Every year 

 the water brought in by the rivers, which are in flood during the monsoon, 

 forms a lake some 60 square miles in area and 2 to 3 feet deep. The 

 water, which is fresh when it first comes in, takes up salt from the accumu- 

 lated stocks in the silt and forms a strong brine, which is partly led into 

 prepared enclosures (Jcyars) for the separation of the salt by solar evapora- 

 tion, partly isolated by temporary reservoirs constructed and cut off bodies 

 of the lake-water in anticipation of the recession towards the centre during 

 evaporation, and partly forms a thin crust of white glistening salt on the 

 bed of the lake, where it is allowed to remain until the arrival of the next 

 monsoon and the usual annual flooding of the lake." 



" During the past few years the quality of Sambhar salt is said to have 

 depreciated, and it has been suspected that the large quantities which 

 have been removed have at last made an impression on the great stores of 

 salt which must have accumulated in the lake silt, appreciably raising the 

 proportion of the associated compounds sodium sulphate, sodium carbonate 

 and potassium sulphate." 



In the Records of the Geological Survey (1905, xxxii., 81 ; xxxiii., 

 100-2) will be found a highly instructive refutation of the opinion 

 that the supply from Sambhar was decreasing. " The rise in the pro- 

 portion of other salts is small and possibly at present unimportant ; the 

 rise in the level of the silt is perhaps more serious ; but, whatever may 

 be the cause, it would be humiliating to watch the failure of this lake, 

 when one knows for certain that it contains, in its uppermost 10 feet of 

 silt, enough salt to supply the requirements of this section of the Salt- 

 Department for another 300 years." 



Ashton explained that the manufacture of salt at the lake is dependent 

 upon the monsoon rainfall. " This," he says, " greatly varies from year 

 to year, and the outturn of salt fluctuates in accordance with the quantity 

 of the brine in the lake. The greatest quantity produced in any one year 

 has been about 260,000 tons, and during a year of excessively heavy 

 rainfall only about 3,300 tons were obtained." 



After Sambhar, the Pachbadra salt source is next in importance. This 

 is situate in Jodhpur (Marwar, as it is well named the land of death). 



966 



Density. 



Taken over 

 by Government. 



Description. 



Salts Present. 



Method of 

 Separation. 



Supposed 

 Depreciation. 



Kefutation. 



Influence of 

 the Monsoons. 



Maximum 

 Production. 



Pachbadra. 



