 Although its destructive force was widely recognized by the 11th century, gunpowder continued to be known as a "fire-drug" (huo yao) because of its original intended pharmaceutical properties.However soon after the chemical formula for gunpowder was recorded in the "Wujing Zongyao" of 1044, evidence of state interference in gunpowder affairs began appearing.Realizing the military applications of gunpowder, the Song court banned private transactions involving sulphur and saltpeter in 1067 despite the widespread use of saltpeter as a flavor enhancer, and moved to monopolize gunpowder production.