ARSENIOUS • FREE TRANSLATOR.ORG • Definition of Arsenious

... roasting arsenical ores, and refining the material (crude arsenic), which condenses in the flues. Arsenic itself is volatile, and many of its compounds have the same property. It forms two well-defined series of salts, corresponding to the oxides: arsenious oxide (As{2}O{3}), and arsenic oxide (As{2}O{5}). These combine with bases to form arsenites and arsenates respectively. Boiling with nitric acid converts the lower into the higher oxide; and powerful reducing-agents, such ...

— A Textbook of Assaying: For the Use of Those Connected with Mines. • Cornelius Beringer and John Jacob Beringer