It deserves also to be remarked, that the real saltpetre, as soon as it became known, was named also nitrum; but, by way of distinction, either sal nitrum, or sal nitri, or sal petre. The first appellation, from which our ancestors made salniter, was occasioned by an unintelligible passage of Pliny, which I shall afterwards point out. The two other names signify, like sal tartari, sal succini, a salt which was not nitrum but obtained from nitrum. Sal nitri, therefore, or salniter, was that salt which, according to the representation of the ancients, was separated by art from nitrum, yet was essentially different from the nitrum or mineralised alkali commonly in use. Biringoccio says expressly,* that the artificial nitrum, for the sake of distinction, was named, not nitrum, but sal nitrum.

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