804 Specimens of the Soil and Salt from [Dec, 



Samples A Nos. 25 and 26, called good and superior salt in the list, when 

 tested, gave traces of sulphate ; with this exception the crystals are good and 

 pure. 



The conclusions to be drawn from the preceding details are some- 

 what at variance with the general impression regarding the Sambhur 

 salt lakes. At least my own idea, derived from conversation with 

 natives engaged in the salt traffic, was, that the lake water was a deep 

 saturated brine, which left so thick a cake of salt on evaporation in 

 the hot weather, that it was cut out in blocks on the margin and 

 brought away on bullocks. 



It would seem, however, that the shallow lake, or inundation 

 would of itself, leave a deposit too thin to be profitably worked ; 

 and tbat it is customary to dig reservoirs or kiydrs wherein sever- 

 al feet depth of water already nearly concentrated to brine, are al- 

 lowed to deposit their crystals on drying ; or the evaporation is 

 aided by the introduction of sticks, up which the saline incrustation 

 rapidly creeps. 



The velocity of the spontaneous evaporation under the fierce sun 

 and scorching winds of the western desert, is well exemplified by 

 specimens A 15, the bacheh or infant crystals of one day's growth, 

 through 16, 17, 18, to 19, the 8th day's produce; in the last the 

 crystals are cubes of full half an inch base. Again we find crystals 

 of the same size in No. 22, from the evaporation of 8 out of 12 

 fingers' depth of water in 20 days of the hottest season. In No. 23 

 the crystals from 6 inches depth of water are of ^ inch base. The 

 size, however, of the crystals depends greatly upon the undisturbed 

 continuation of the process, and does not give us a clue to the quan- 

 tity of salt deposited from a given depth of water, whence we might 

 calculate the saltness of the lake itself at various periods of the sea- 

 son. The rate of evaporation itself may be estimated from the above 

 data tolerably well ; thus — " 6 fingers in 8 days" — " 12 fingers in 20 

 days" — will be nearly half an inch in depth per diem ! The pits dug 

 for the reception of the brine seem sometimes to be very deep, 10 or 12 

 feet ; in these when deserted the deposit proceeds for several years, 

 forming solid strata of salt separated by a streak of earth washed in 

 during the rainy season. The accumulation is then dug out in mass : 

 but in general the salt for sale is collected as it forms in the brine 

 pits in a granular state, by which means it is freed from the more 

 soluble salts with which it is accompanied. The pakka salt of the 

 byopdris or traders (Nos. 25, 26), is of a large grain — the latter 

 indeed in half-inch crystals, — and not very clean. 



