She spun around, aghast, “white, as the saying goes, as a ghost,” Leibniz quotes the astronomer as saying.

And she cried: “You mustn’t touch that!”

And he, although he suspected, correctly, that he already knew the answer, said: “What a pretty song! Where did you learn such a pretty song?”

And she, although she wished, clearly, to continue frowning, could not suppress a small smile: “I learned it from Heinrich.”

And he cried: “From Heinrich, yes, I thought so! I thought from Heinrich! And where is Prince Heinrich now?”

Her smile vanished. “Heinrich’s in heaven now. You don’t know that?”