Definition of nitre:

part of speech: noun

Saltpetre or nitrate of potash, a crystalline substance of the appearance of salt, extensively used in the manufacture of gunpowder.

Usage examples:

• She replied, in a dignified manner, that she had made it to divert herself with the crystallization of the silver, spirit of nitre and mercury, and that she looked upon it as a piece of metallic vegetation, representing in little what nature performed on a larger scale; but she added, very seriously, that she could make a Tree of Diana which should be a very Tree of the Sun, which would produce golden fruit, which might be gathered, and which would continue to be produced till no more remained of a certain ingredient. Jacques Casanova de Seingalt in "The Memoires of Casanova, Complete The Rare Unabridged London Edition Of 1894, plus An Unpublished Chapter of History, By Arthur Symons".

• They would remember the treasure he had wrung from their distress; the cotton bought for ten cents and sold abroad for a dollar; the nitre the gunpowder, the clothing and medicines, rated so mercilessly dear; the profits boosted a thousand per cent. Eugene P. (Eugene Percy) Lyle in "The Missourian".

• In this and in a subsequent communication in Volume I of Silliman's Journal he described the process of nitre manufacture in caves, and gave the best theory of its formation, according to the science of the day. Robert Peter in "The History of the Medical Department of Transylvania University".

• Thoroughly burned charcoal, distilled sulphur, and the purest nitre are powdered and mixed in a revolving drum, made into a paste with water, put under great pressure between sheets of gun metal, granulated, sifted, to separate the coarse and fine grains, and glazed by revolving in a barrel which sometimes contains a little powdered graphite. R.P. Williams in "An Introduction to Chemical Science".