Noun
a white salt used in dry cells
Source: WordNetsal-ammoniac
Nitrogen also occurs in some relatively uncommon minerals, such as saltpeter (potassium nitrate), Chile saltpeter (sodium nitrate) and sal ammoniac (ammonium chloride). Source: Internet
In the 15th century, Basilius Valentinus showed that ammonia could be obtained by the action of alkalis on sal ammoniac. Source: Internet