ALKALI, POTASH, AND GUNPOWDER.

155

name of the salt, nit rum, was derived from the Egyptianname, a province Nitra, where, he says, it was obtained ingreat abundance, or whether the province derived its namefrom that substance. Among the Greeks, Galen, we believe,asserted that by incineration, this alkali became slightlycaustic, becoming also deliquiesced if exposed to the air.

In a similar manner saline ashes were obtained from otherplants, although, perhaps, essentially different from theformer; those salts last alluded to, in process of lime, ob-tained among Europeans the name of pot-ash, by which is ,understood the vegetable alkali.

For previous reasons, it may not appear strange that thedistinction of mineral and vegetable salts, or alkaline sub-stances, was not made by the ancients, especially when it isconsidered, that they occasionally obtained salts from vege-table and mineral substances. There is reason to sup-pose, they also considered the saline incrustation of oldwalls, called by the Levitical* law the plague of houses, ascommon with the other saline substances, and that they de-nominated this nitrum also. All those species of this salt,it is probable, they used for the domestic purposes of wash-ing, and thence farther may be thought to be referred untoby the prophet Jeremiah, ch. ii. v. 22, and likewise in theProverbs of Solomon, ch. xxv. v. 20, also in Malachi, ch. iii.v. 2. The antiquity of this name is unquestionable fromthese texts, and also from one of the early fathers of theChristian church, who thus expresseth himself on a passagein Proverbs, ch. xxv. v. 20. “ Nitrum a Nitria provincia,

ubi maxime nasci solet, nomen accepit. Nec multum asalis Ammoniaci specie distat. Nam sicut salem in litore marisfervor solis conficit, durando in petram aquas marinas, quasmajor vis ventorum, vel ipsius maris fervor in litoris ulterioraprojecerit; ita in Nitria, ubi aestate pluviae prolixiores tellu-rem infundunt adest ardor sideris tantus, quod ipsas aquaspluviales per latitudinein arenarum concoquat in petram;salis quidem vel glaciei aspectui simillimam; sed nil gelidirigoris, nil salsi saporis liabentem, quae tamen, juxta naturamsalis, in caumate durare, etin nubiloso aere fluere ac liquefierisolet. Ilanc indigen® sumentes servant, et ubi opus extiterit,pro loinento utuntur. Unde Judaeo peccanti dicit prophetaJeremias: si laveris te nitro, et multiplicaveris tibi herbamborith, maculata es in iniquitate tua, dicit Dominus Deus. Cre-pitat autem in aqua quomodo calx viva; et ipsum quidem dis-perit, sed aquam lavationi liabilem reddit; cujus natura cuisit apta figur®, cernens Solomon ait: Acetum in nitro, qui

4 Leviticus, ch, xiv. v, 33.