Saltpetre.

Manawatu Herald, 16 February 1892, Page 2

Saltpetre.

The Germans have discovered immense fields of saltpetre in their African possession 3. Potassia, nitrate of potash, is the propar term for the

r ; 3le known. in commerce as saltetre. The common name is derived . ,■• rom sal pet roe, salt of the rock. It 3 found usually in thin white subransparent crusts, and in needleform rystals on old walls and in caverns, toccurs in many of the caverns of Kentucky and other Western > tates, „,,.~,.« cattered through the earth that orins the floor of the cave. *In proinring it, the earth is lixiviated made into a lye of ashes, water, fee i, and the lye, when evaporated, fields the saltpetre. India is its nost abundant locality, where it is )btamed largely for exportation. , Spain and Egypt also afford large inantities of nitre . foiv oommerce. rhis salt forms on the ground in r the aot weather succeeding cdpipus^rains, j.nd appears in silky tufts or efflor- , 3scences ; these are brushed up by a kind of broom, lixiviated, and after settling, evaporated and crystalized. En France, Germany, Sweden, Hungary and other countries there are artificial arrangements called nitriarm, or niter beds, from which niter is obtained by the decomposition mostly of the nitrates of lime and , " magnesia which form in these beds. Refuse animal and.^ vegetable matter piitrified in contact with calcareous 1 ' soils produces nitrate of lime, which • ' affords the niter by reaction with ' carbonate of potash. Niter (saltpetre) was first manu- "' factured in England in 1825. It is employed in making gunpowder, forming 75 to 78 per cent in shooting powder and 65 in raining powder. It is also extensively used in the manufacture of nitric and sulphuric acids ; also for pyrotechnic purposes, fulminating powders, and sparingly « in medicine. In India it is used for a cooling mixture, an ounce of powdered nitre in five ounces of water reduces the temperature 15 degrees. ; The chief employment of Paotashsaltpetre is in the manufacture, of gunpowder, as the nitrate of soda found in large beds, in Peru, 'has superseded its use in the manufacture of sulphuric acid. •