213 COTTER: SODA INDUSTRY OF SIND. 



Those which are more concentrated have a peculiar smell resembling 

 thai of decaying fish, while the water is of a red colour. 



T. M. Chatard 1 ascribes the red colour of alkaline lakes to the 

 presence of a crustacean (Anemia salvia), which however is not 

 known to occur in India. The red colour of the saline Sambar 

 Lake in Rajputana is due, according to the researches of the Salt 

 Department to algae. 



The Sind dhands are subject to considerable seasonal variation 

 in depth, being at their fullest after the monsoon rains, and lowest 

 in May or June, just before the break of the rains. The verv small 

 or very shallow dhands dry up completely ; the large dhands shrink 

 considerably but do not as a rule dry up or become sufficiently 

 concentrated to deposit their dissolved salts ; it is only those dhands 

 which are of a medium size, and shallow depth which deposit their 

 soda without drying up completely ; from these the best quality 

 of soda is obtained, while those dhands which dry up completely 

 yield much more impure deposits. 



Turning now to the dhands near Kot Jubo, the majority of 

 which are alkaline, a few saline, and a few fresh, it may be worth- 

 while to explain their connection with the dra-ins, and the source 

 of their water. 



An examination of Plate 16 will show that the country east of 

 Kot Jubo is for the greater part covered by two large sand-plateaux 

 or dra-ins, that to the west being known as the Kharori or Pur 

 Chandar jo dra-in, and that to the east as the Sanoi je dru-in. 

 Between these two dra-ins is a belt about two miles in breadth of 

 bhit and tali running in a N.N.E. direction, and extending for over 

 12 miles in length. South of Kot Jubo and Pakhyaro dhand, 

 the dra-in gives place to bhit and tali type of country. North of 

 Kinri and Sahai dhands again the dra-ins diminish in breadth while 

 the bhit and tali type of country becomes more common. 



It is very evident that these two large sand-plateaux or dra- 

 ins form reservoirs of a kind for the absorption of the monsoon 

 rains. The presence of fresh-water at the bottoms of the numerous 

 kochurs, and the presence in the very middle of the Pur Chandar 

 jo dra-in of sims of fresh water shows that water is abundant in 

 the lower levels of the sand of ^he dra-in. As a result, the Pur 



1 " Natural Soda ; iti Occurfenoe and Utilization'' Bull. U. S. Geol Surv 

 No. 60, 1890, p. 95. 



