perhaps to the infusoria inhabiting it, oozes up to the surface from the east side of the valley, whence it flows in rills and rivulets down to the lakes.
In these basins the waters increase till the end of December, by which time they have attained a depth of about 5 feet. Then they subside, leaving some of the cavities quite dry. Their composition varies with the different basins. In some marine salt prevails, in others carbonate of soda; while the sulphate of soda is intermingled in diverse proportions. Two of the lakes, presenting a reddish appearance when dried up, leave an encircling ring of red or brown salt, which emits the pleasant fragrance of the rose. The decomposition of the marine salt by the carbonate of lime contained in the moist soil produces crystals of soda, which
Scale 1: 250,000.
are deposited in a greyish layer, and which are collected by the natives of Terraneh, a village on the left bank of the Rosetta branch of the Nile.[1]
A few springs of fresh water, which have their source in the neighbouring rocks, help to support a scanty vegetation, mainly comprising Mediterranean species and a few sickly palm-trees. The only inhabitants of the Natron district are the inmates of the Baramus, Saint Macarius, and other convents founded in the fourth century of the Christian era, at a time when thousands of monks took refuge in the caves and valleys of this rocky and sandy region. Like the old anchorites, the recluses of the Natron Valley are forbidden to consume the pro-
- ↑
Natron of the Terranch lakes, according to Berthollet: —
Chloride of sodium 52 per cent. Sand 3 per cent. Carbonate of soda 52 " Carbonate of lime 0-9 " Sulphate of soda 11 " Oxide of iron 0-2 "
