When the waters evaporate in the summer they leave a clay bed of remarkable hardness, which is sometimes encrusted with saline matter of a snowy whiteness and dazzles the eyes of the traveller.
Way about 1850, this precaution was not only superfluous but harmful, because the soil possesses a power of absorbing the soluble saline matters required by plants and of retaining them, in spite of rain, for assimilation by the roots.
The casein, which forms the principal constituent of cheese, and a certain proportion of albumen which is present, form the nitrogenous, while the complex saline substances and water are the mineral constituents.
Although saline springs are mentioned here as early as the 13th century, the first attempt to bore for salt was not made until 1839, while the systematic exploitation of the salt-beds, to which the town is indebted for its prosperity, dates only from 1856.
The ri entral tract was a lower plain, covered with loose ashes and e riarked by a few pools of hot and saline water.
The ancient practice of transfusion has been placed on a more intelligible footing, and by the method of saline injections made more manageable as a means of relief or even of cure.
West of Abu Dhabi a low flat steppe with no settled inhabitants extends up to the Katr peninsula, merging on the north into the saline marshes which border the Persian Gulf, and on the south into the desert.
The great plain in Sheng-king is in many parts swampy, and in the neighbourhood of the sea, where the soil emits a saline exudation such as is also common in the north of China, it is perfectly sterile.
On the west, in the dry region, this is occupied partly by the alluvial deposits of the Indus and its tributaries and the saline swamps of Cutch, partly by the rolling sands and rocky surface of the desert of Jaisalmer and Bikaner, and the more fertile tracts to the eastward watered by the Luni.
Minute vesicular cavities are not infrequently present, sometimes as negative cubes, and these may contain saline solutions or carbon dioxide or gaseous hydrocarbons.