Shake all the ingredients well with ice and strain into a chilled wineglass. Garnish with the grated nutmeg.
I adapted this recipe from the White Plush, a drink of whiskey and milk, in How to Mix Drinks by Jerry Thomas (1862). The White Plush was named after a gullible New England buyer, as Thomas tells it, who was hustled by a couple of dry-goods salesmen in New York City. They convinced him he was drinking milk and seltzer, a popular local favorite. When the whiskey started to take hold, he knocked over his "milk" and stared at it a moment, then remarked, "Gee, it looks just like white plush." This prompted the two slicks to order "another yard of white plush for the gentleman" from the knowing bartender.