262 SAND OF THE DESERT. 



crystals of muriate of soda : and. on the surface of the 

 water, films accumulating till the whole amounts to a con- 

 siderable thickness. The soil of the lake is dark-brown 

 muddy sand, approaching to black, of a viscid consistence 

 and slimy feel ; and, on the lately uncovered surface of 

 the banks, a black substance, something like mineral tar, is 

 seen oozing out. The water begins to increase in winter, 

 and is at its height in the spring. In the beginning of the 

 winter the trona is thickest and best ; but in the spring it 

 disappears entirely. The size of the lake has diminished 

 considerably within the last nine years, and, if care be not 

 taken, the diminution will be still more considerable ; for 

 plants are making rapid encroachments, and very shallow 

 banks are observable in many places. On making inquiry, 

 I found the quantity of trona has not sensibly dimmished 

 for the last ten years. Perhaps it may appear so, from there 

 always being sufficient to answer every demand. The 

 quantity annually carried away amounts to between 400 and 

 500 camel-loads, each amounting to about 4 cwt., — a large 

 quantity, when the size of the lake is taken into account. 

 It is only renioved from the lake when a demand comes. 

 A man goes in, breaks it off in large pieces, and those on 

 the banks remove the extraneous matter, and pack it in 

 large square bundles. The water in the valley is good, 

 being free from saline impregnation." — Clapper ton, Den- 

 ham, and Oudneifs Journal, p. 57. 



Fulgurite and Meteoric Iron found in the Desert. — In some 

 parts of the Desert, tubes of sand, resembling those found 

 at Drigg, in Cumberland, and in different sandy districts on 

 the continent of Europe, are met with. They are named 

 fulgurites, or lightning-tubes, by naturalists, and are sup- 

 posed to be formed by the lightning striking through the 

 sand, and partially melting portions of it. Masses of me- 

 teoric iron also have been met with in the Desert. Gol- 

 berry, in his journey through Western Africa, in the years 

 1805-7, mentions his having found a mass of meteoric iron 

 in the Desert. Fragments of it were brought to Europe 

 by Colonel O'Bara, and were analyzed by Mr. Howard, who 

 found it composed of ninety-six parts of iron and four ^of 

 nickel. 



Observations on the Sand of the Desert. — ^Having now 



