[ 57' 1 



948. The use of gypsum as a manure was known to the 

 Greeks and Romans. It is largely used in Europe and 

 America for manuring potatoes and clover. It is very desir- 

 able to extend the use of this substance for manure in India 

 especially for clay soils. It benefits arahar, gram and other 

 pulse crops, tobacco, rhea and potatoes. It should not be 

 used annually, but once in 3 or 4 years, on the same soil at 

 the rate of 5 to 10 mnds. per acre. It is a more useful 

 manure than lime, the sulphur of CaSO 4 being also an essen- 

 tial constituent of plant-food. 



949. _Salt. The chief native sources of common salt 

 in India are, (i) the salt lakes and pits of Rajputana ; (2) the 

 salt mines of the Salt Range of the Punjab and (3) the sea 

 and the estuaries. 



950. The evaporation salt of Rajputana is derived from 

 the Sambhar Lake, the Didwana Lake and the Pachbadra Pits; 

 The Sambhar Lake is the most important of these three. It 

 is situated on the borders of the Jaipur and Jodhpur States, 

 It is a shallow sheet of water 20 miles long and 2 to 7 miles 

 wide and only i to 4 ft. deep when full. The salt obtained is 

 very pure and is largely used in the N.-W. P., Oudh, Raj* 

 putana and the C.P. The working season is between Novem- 

 ber and May. The lake is leased by Government from the 

 Jaipur and Jodhpur States for Rs. 7,00,000, with, in addition, 

 a royalty of 40 per cent, of the price of salt sold in excess of 

 63,135 tons, which adds the payment of about another two 

 lakhs of rupees. There are 3 kinds of salt produced at 

 Sambhar : (i) Kyar-szh, which is produced in permanently- 

 walled compartments within the lake whence soft earth is 

 carefully removed and which are kept supplied with brine.- 

 (2) Pan-salt, which is produced in shallow basins along 

 the shores, which are kept supplied with brine with 

 hand-pumps or swing-baskets. (3) Lake-salt, which is 

 formed spontaneously in the bed of the lake as the water 

 evaporates, 



