1^8 DESCRIPTIONS OF EGYPT. 
white of the masses of natron, and the grey dusky 
gravel of the desert* These lakes are frequented 
by the cameleon, the antelope, and vast numbers 
of aquatic fowls, among which the flamingo is re- 
markable for the brilliancy of its plumage* 
The natron lakes, which are seven in number, 
are separated by banks of sand. In the dry sea- 
son, they shrink into small detached ponds, but 
when the water rises highest, they are united in 
one great lake, which occupies a space of six 
leagues in length, and covers the whole breadth 
of the valley. When the water retires, and the 
lakes separate, the ground which is exposed is 
covered with a saline sediment, which hardens in 
the sun, chrystalHzes, and forms the natron. The 
thickness of the saline stratum varies with the 
period of the inundation, and where it is of short 
continuance, the natron appears only as a slight 
efflorescence, like flakes of snow. The water is 
sometimes covered with this saline substance ; 
and Granger relates, that at the end of August, 
when he visited these lakes, the superficial crust 
was sufficiently consolidated to allow his camels 
to pass over its surface* In this immense natural 
laboratory of soda, the original substance from 
which the natron is formed, according to Berthol- 
let, is common sea salt. According to the Arabs, 
the soil impregnated with natron extends to the 
distance of twenty days' journey into the desert. 
