''Aphronitre'', or aphronitrum, is a kind of

nitre Niter or nitre is the mineral form of potassium nitrate, KNO3. It is a soft, white, highly soluble mineral found primarily in arid climates or cave deposits. Potassium and other nitrates are of great importance for use in fertilizers and, ...

, mentioned in ancient texts. It was supposed to be the foam or froth of a liquid, emerging to the top. Naturalists have taken the ancient ''aphronitre'' to have been a native

saltpetre Potassium nitrate is a chemical compound with a sharp, salty, bitter taste and the chemical formula . It is a potassium salt of nitric acid. This salt consists of potassium cations and nitrate anions , and is therefore an alkali metal nitrate ...

References

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digicoll.library.wisc.edu

References

See also