SALINE SOILS occur in many parts of British India, in Hindustan, in the Dekhan, and in the Ceded Districts. In Northern India they are known as reh (q.v.), and salts of soda are largely manufactured from them.
Impure carbonates of soda, known as rasi and sajji, are manufactured from veil soil. Rasi is obtained by lixiviating the reit and concentrating the brine by solar heat. Sajji is the fused solid obtained by mixing reh with water, and exposing it in a furnace to artificial heat. The products from both processes aro crude Carbonate of soda, and these are largely used in the manufacture of soap and tobacco.
Itch soil tracts have intermixed .patelies of salt soil and saltpetre soils, and if these soils aro inter mixed with the reh in the manufacture of sajji or rasi there will be no formation of salt. Reh soil, however, where genuine or pure, differs from the other soils containing sulphate of soda and saltpetre, as it contains n.o common salt.
An ordinary factory worked by five or six men will, in one season, produe,e over 250 British man or maund of crude carbonate of soda.
Glatther's salt is known in N. India rut Khari, also Kliari-nun. Its manufacture in by filtration and solar heat. The machinery requisite consists of a filter (chan tut), reservoira (hauz or bandit), a shallow masonry pan (patta) 14 yards by 12 yards and from 5 to t, inches deep, !mule of consolidated kanknr, with a thick surface coating of lime-plaster. The patta or inasonry
subdivided into four or five compartmenta Oiyari) on. ditTerent levels to facilitate transfer of tho fluid. These are constructed on a tmct of khari soil, where water is conveniently at hand, and ill the early part of March work is commenced. The soil ia gathered and taken to the factory, passed through the filter, and the compartments filled with the brine, and exposed to the action of the sun. On the second or third day, the contents of ono compartment are run off into the others; one after another is thus emptied, until all the concentrated brine is collected in one compart ment for the Glauber's salt to precipitate. The empty compartments are filled with fresh brine.
In the soil there is always a percentage of common salt, and during the evaporation the sulphate of soda first precipitates ; secondly, tho chloride of sodium. It is thus an easy matter to remove the tipper layer of salt from the glauber beneath, and this is usually done.—Carnegy.