Never mind a Fountain of Youth. Right now we find ourselves in need of a rather more pressing therapy. Without wishing to be impertinent, in Europe it does feel as though the insidious economic peril of coronavirus--quite apart from its biological impact, deadly as that can be--has been grasped rather more urgently on one side of the Atlantic than the other. That's perfectly understandable, given its unexplained foothold in Italy at a time when the U.S. President could still declare that domestic cases would "within a couple of days... be...