40 Dr. Verchere on the Geology of Kashmir, [No. 1, 



in 10,000 parts of water ; the saline matter is sulphate of soda and 

 sulphate of lime. Another lake, the Karso-Talao, about 6 miles 

 long, is reported by the same gentleman to contain a great deal of 

 chloride of sodium and sulphate of soda, with a little carbonate of 

 lime and carbonate of soda. These two lakes are said to be sur- 

 rounded by mountains of crystalline rocks, principally mica-schists 

 and granite. But one of the most interesting subjects connected 

 with the geology of Rukshu is the existence of borax in the valley 

 of Puga. The manner in whieh it occurs as an efflorescence is too 

 well known to require description here, but one cannot but regret 

 that Mr. Marcadieu's report is not more geological ; indeed it can 

 only be regarded as chemical, and the geology of the district is still 

 a work to be done. I have never visited Puga, but, from the 

 several descriptions of it I have read, I am satisfied that the borax 

 ground is the bottom of a dried up lake. The analysis of impure 

 borax collected at Paga shows it to contain, besides borax, sulphate 

 of soda, sulphate of lime, chloride of sodium and carbonate of soda. 

 These impurities are precisely the composition of the Kullur salt 

 of the plains of the Punjab and of the saline matter of many hot 

 springs and salt lakes of the Himalaya and the Salt Range, and it 

 appears to me evident enough that the lacustrine mud which fills 

 up the bottom of the Puga valley, is similar to the alluvial deposit 

 of the Punjab. Boracic acid, which probably once rose freely to 

 the surface of a small lake and was deposited in an uncombined state, 

 is now arrested by the bed of lacustrine mud which fills up the 

 fumarole and combines with some of the salts of soda. It appears 

 therefore much to be regretted that an attempt was not made to 

 estimate the thickness of the lacustrine deposit and that a few wells 

 were not sunk into the borax ground and the Avaters and gases 

 which mi°hit have been collected in these wells carefully examined ; 

 possibly such researches and experiments might have led the way 

 to an increase of the present supply, and to a system of collecting the 

 borax or boracic acid sufficiently pure not to require refining. 



76. In Ladak, R/ukshu, Sooroo and Zaskar, no fossils were ever 

 found ' as far as I know, older than those of the carboniferous forma- 

 tion. But if we follow the great valley, betiveen the Kailas Range 

 and the Ser and Mer chain towards the S. E. we find, on the other 



