Gradually, the notion of nostalgia attached itself almost exclusively to soldiers—Swiss mercenaries being very popular hires in armies across the continent and doctors being a regular part of army life. It would take a little more than two centuries for doctors to figure out that there might be something more than a mysterious nerve disorder causing young men whose sole job was dismembering other humans and dying gruesomely to yearn for the comforts of home; in the meantime, cures and coping methods grew a little more creative. There are stories, including one from Jean-Jacques Rousseau’s Dictionnaire de musique, of foreign officers banning the playing of Swiss ranz des vaches—cow-based folk songs historically played by herdsmen on horns as they drove their cattle down from mountain pastures—and even the sound of cowbells, lest they paralyze troops in nostalgic reverie. (It became a tenet of folk wisdom about the Swiss that the ranz des vaches had this power over them; it featured as metaphor or plot point in eighteenth- and nineteenth-century philosophical dialogues, dramas, poems, and operas, particularly by German Romantics, who were constitutionally interested in a disease that spoke so acutely to our conceptions of self.)
By the 1800s, the terrors of nostalgia finally spread to other countries’ soldiers. To stop the spread of the disease, Russian physicians recommended burying alive anyone who started showing symptoms—which apparently did prove quite effective. On the other side of the Atlantic, the American Civil War saw several outbreaks among young fighting men even though they technically had never left their homeland, per se. Their physicians were a bit kinder, suggesting that occasional removal from front line fighting would bolster their spirits (not that the doctors didn’t also suspect that nostalgia betrayed a deep flaw in a soldier’s character). The American army apparently continued furtive explorations of the concept all the way up to the Second World War, chiefly as a way to reduce desertion, and nostalgia maintained some interest for psychologists and psychiatrists in the first half of the twentieth century, albeit in a downgraded form: it became less disease than symptom or even disposition, usually of people who had far bigger and more immediate problems. (A 1987 survey of its common historical-psychological invocations cited “acute yearning for a union with the preoedipal mother, a saddening farewell to childhood, a defence against mourning, or a longing for a past forever lost.”) Yet, despite these last tendrils, the civil war was really the last time anybody was diagnosed as a nostalgic, as such: nostalgia was largely abandoned by the medical community by the last decades of the nineteenth century. This seems to have had less to do with any particular breakthroughs regarding brain structure or mental health than with the general inability of anyone to make meaningful headway on understanding, let alone curing, nostalgia.