The oldest and best known of these are the Natron lakes in Lower Egypt.
A chain of natron lakes (seven in number) lies in a valley in the western desert, 7oto 90 m.
Finding vegetable alkali in certain minerals, such as leucite, proposed to distinguish it as potash, and at the same time assigned to the mineral alkali the name natron, which survives in the symbol, Na, now used for sodium.
The first is that of the natron lakes already mentioned.
The fire may well have caused the natron, an impure form of carbonate of soda, to combine with the surrounding sand to form silicate of soda, which, although not a permanent glass, is sufficiently glass-like to suggest the x11.4 FIG.
The story that Phoenician merchants found a glass-like substance under their cooking pots, which had been supported on blocks of natron, need not be discarded as pure fiction.
The proportions of the salts of river and sea-water are quite different, as Julius Roth shows thus: - The salts of salt lakes which have been formed in the areas of internal drainage in the hearts of the continents by the evaporation of river water are entirely different in composition from those of the sea, as the existence of the numerous natron and bitter lakes shows.
The rift-valley faults continue down the depression, marked by numerous volcanoes, in the region of the Natron Lake and Lake Manyara; while the steep walls of the deep depression of Tanganyika and Nyasa represent the western rift system at its maximum development..
Sodium carbonates are also widely dispersed in nature, forming constituents of many mineral waters, and occurring as principal saline components in natron or trona lakes, as efflorescences in Lower Egypt, Persia and China, and as urao in Mexico, Colombia and Venezuela.
60 An interesting discovery of the late period in Upper Egypt, that of images and other temple objects of precious metals, was also made at Dendera by the diggers for natron (sebakh) and recovered by the Service des Antiquites for the Cairo Museum.61 Outside Egypt proper the work of editing and publishing all the Egyptian inscriptions of Sinai has been begun by Dr. Gardiner and Mr. Peet.62 A worthy completion of the record is the wonderful exhibition of all the finest examples of Egyptian art in Britain outside the British and Ashmolean Museums, held by the Burlington Fine Arts' Club in London in the summer of 1921.63
North-west of Kilimanjaro is a sheet of water known as the Natron Lake from the mineral alkali it contains.
Both these hydrates occur in the mineral kingdom, the former as natron and the latter as thermonatrite.
Here in one portion of the desert, named Cellia, the monks lived a purely eremitical life; but in Nitria (the Wadi Natron) they lived either alone, or two or three together, or in communities, as they preferred.
The corpse was treated with natron and asphalt, and wound in a copious swathing of linen bandage, with a mask of linen and stucco on the face.
South of the Wadi Natron, and parallel to it, is a sterile valley called the Bahr-bela-Ma, or River without Water.
The salt obtained from Lake Mareotis at Meks, a western suburb of Alexandria, supplies the salt needed for the country, except a small quantity used for curing fish at Lake Menzala; while the lakes in the Wadi Natron, 45 m.