Note 51 bis — Chapter VI · TTHE COMPOUNDS OF NITROGEN WITH HYDROGEN AND OXYGEN
George Kamensky translation
Leroy (1889) obtained KNO2 by mixing powdered KNO3 with BaS, igniting the mixture in a crucible and washing the fused salts; BaSO4 is then left as an insoluble residue, and KNO2 passes into solution: 4KNO3 + BaS = 4KNO2 + BaSO4.