252 ME. A. WADE ON THE [May 1911, 



and Cheshire districts. It may be that the presence of the salt 

 is not entirely due to the evaporation of a sea-water film. All 

 along the edge of the sea was a white spume which accumulated 

 continuously from the air-bubbles left behind by retreating waves. 

 This frothy material was intensely salt. After standing some time, 

 the water partly evaporated, leaving behind a more saline and sticky 

 white mass, which was constantly being blown inland over the 

 sand. In this manner enormous quantities of salt must be carried 

 inland, and deposited among the sands of the desert. 1 Sometimes 

 stones were found at some distance from the sea, coated with a pure 

 white encrustation of salt : in these cases the salt had evidently 

 been carried inland by the wind. On the northern coast of Gay sum 

 Island several patches of snow-white salt crystals, perfectly formed 

 and frequently measuring 5 to 10 mm. in diameter, are to be seen 

 at a height of 20 to 30 feet above sea-level. Here, again, the 

 salt was carried in as foam. Saline encrustations were found on 

 the fossils of the raised coral-reefs of the Jubal group of islands, 

 almost 200 feet above sea-level. 



I append analyses made of the saline sand from the shores of 

 the Gulf of Jemsa. (The spectroscope revealed the presence of 

 abundant sodium with some calcium. Potassium was faintly 

 indicated.) 



Sample No. 1. 



'.. Bulk Analysis. Percent. 

 Na.,0 (with some K 2 0). 25*02 

 CaO 343 



I. 

 II. 



Sample No. 2. 

 Bulk Analysis. 



Percent. 

 23-40 





... 514 



MgO P47 



Fe o 0, 2-40 



SiO 3320 





1-42 





... 9-90 





... 23-78 



CI 2 28-52 





.,. 30-80 



SO, 4-85 





... 4-52 



CO 3-12 





HO 1-74 





... 6-76 





Water extract. 



CaO 



Na,0 



CI 



MgO .., 



Acid extract. 

 Si0 2 





Totals 103-75 



105-72 



I. 



Matter removed by solution 



in warm dilute HC1... 61-91 



Eesidue insoluble in dilute 



HC1 34-20 



... 2-14 

 ... 23-40 

 ... 30-80 

 . . . trace 



HO 174 





CO 3-10 







... 23-78 



Total 100-95 



CaO" 



... 3-00 



Fe O 



9-90 





MgO 



so, 



... 1-42 

 ... 4-42 



[The results total more than 100 per cent., because the sodium is returned as 

 oxide. The amount of sodium in Sample 2 is equivalent to 26'50 per cent. 

 of sodium chloride, and the calcium oxide in the soluble portion is equivalent 

 to 4-25 per cent, of calcium chloride.] 



1 See J. G. Goodchild, ' Desert Conditions in Britain ' Trans. Geol. Soc. 

 Glasgow, vol. xi (1897-1900) p. 85. 



