SALTPETRE, Nitrate of Potash.
Ubkir, . . . . Arum Potassa3nitras, . LAT.
Malh-i-Barut, . . „ Sal-petrze 11 Siau-shi, Mang-siau, CHIN. Santlawa, . . MALAY. Yen-siau, Ho-siau, „ Nitro, . PORT., IT., SP.
Ti-shwang, . . . „ &ultra, . . . . Salpetar; . . DUT., GER. Yavakshra, . . SANSK.
Nitre, ENO , FR Wedi-lunu, . . . SINGH.
Suria-khar, . . . aUJ. Salitre, SP.
Shora, . PERS. Pottil-uppu, TAM., TEL.
The saltpetre of commerce is obtained from the East Indies, chiefly from Oudh, Bengal, and Nellore. Saltpetre exported from India was, in Cwt. Rs. Cwt. Rs.
1874-75, 653,330 50,14,678 1878-70, 382,905 36,17,GGO 1875-76, 915,080 34,89,987 1879-80, 609,372 96,97,968 1876-77, 906,218 38,17,060 1881-82, 354,800 35,94,367 1877-78, 389,002 37,90,017 1882-83, 399,565 38,87,602 It is manufactured in India by lixiviating nitri fied earths, and evaporing the liquor thus obtained either by artificial heat or by tho solar rays. Saltpetre soil is found abundantly on the sur face of nearly all the uncultivated soil in most old towns and villages, within or in the innuediato vicinity of the town or village, also on the sides of roads, and encrusting the walls of houses. The nitrous efflorescence is most abundant during the dry weather front January to June, and is not procurable during the rainy months, or after ram showers. Saltpetre soil always contains more or less common salt, and in Oudh is often intermixed with patches of purely salt earth. The processes of lixiviating, filtering, running off from ono com partment to another, and collecting the crystal lized saltpetre, are similar to those followial in the manufacture of Glauber's salt.
It generally occurs as a white incrustation on the soil, being also mixed with it to a considerable depth. The earth is scraped aud boiled with water. The solution ia then concentrated by the heat of the sun, and the water afterwards eva porated by artificial beat. From this tho salt appears in impure crystals, which are exported in coarse bags of sacking. In this state tho salt is known as rough [saltpetre. The empty bags aro soaked Juni boiled to extruct the salt they may have imbibed, and then sold to the makers of coarse wrapping paper. Its ordinary price is £38 to .£40 the ton, but during the mutinies lit Northern India in 1857 and 1858, it roe° to £59. It is refined by boiling and cooling, the pure crystals forming in the cold solid solution, leaving the impurities still dissolved.
The soil of tho Bellary, Ongole, and Nellore district's is very favourable for the manufacture of saltpetre.
Burma.—Saltpetre is manufactured in several places in Upper Burma to about .r,0 tons annually. It is found in some of the caves of Tenasserim, and is imported front Rangoon. It is manufac tured in China from the natural efflorescence of the soil, but it is largely imported.
In Cuttack nitro is known loe.ally as Kehl jabkhai.
Tho commercial saltpetre examined in 3fadraa has, generally speaking, been very pure, and especially free from -sulphates. It is made at 3loganore and Errode, also of a very fine quality at Ellore.
Pciajab.—A saltpetre la made in most of the gain districts of the Panjab, particularly in Multan, Debra Khan, Jhang, and Gugara, where it eflloresces spontaneously about old ruins, and is collected and purified by boiling and re-crystalliza tion. It forms a considerable article of export, both inlaud, beyond the frontier, and also to the seaports. Saltpetre is found naturally in the soil, in many parts of the Panjab, efflorescing near old buildings. It is not to be confused, however, with the white efflorescence often ob served on the reb, or barren uncultivated lands, and which is usually a sulphate of soda.
Saltpetre and salt are produced abundantly in some parts of Shahabad, and crude saltpetre is prepared at from 6 to 7 rupers per local maund, by the Nooneah workmen ; this, in its crude state, would be £15 to £18 per ton, while the ealt produced with the saltpetre is of a coante kind.
3farsden, in his Suinatra Re.searches, referring to the saltpetre caverns in the country of Cal town, near the land of the Davi river, suites that these caves are filled with nests of innumerable birds of the swallow kind, which abound tho more the further ono advanced into the awe, and that it was their dung forming the soil (in many places from 4 to 6, and even from 15 to 20 feet deep) which affords the nitre. A cubic foot of this earth produced on boiling 7 lbs. 14 ounces of saltpetre, and a further experiment gave one ninth mom—Quarterly Review, July 1868 ; MSS.; Cat. Al. E. of 1857; Cat. Er., 1862; Burckhardt, p. 114; Robinson's Travels, p. 135 ; Marsden &maim; Mason's Tenasserina.