The literary use of "irritancy" often conveys a transient surge of intensity or emotional agitation. In Thomas Carlyle’s narrative, for example, the word is deployed to describe a moment of heightened yet fleeting energy—as seen in the scene where the Queen endures a long night of activities, only for the once-vibrant spark of existence to dissipate like a dying Will-o'-wisp [1]. This usage not only underscores the ephemeral nature of passion and fervor in historical contexts but also adds a layer of metaphorical depth, implying that moments of keen alertness or irritability are as transient as they are vivid.