THE APPARENT IMPOSSIBILITY.
You profess yourself able to show any one what he never saw, what you never saw, and what nobody else ever saw, and which, after you two have seen, nobody else ever shall see.
After requesting the company to guess this riddle, and they have professed themselves unable to do so, produce a nut, and having cracked it, take out the kernel, and ask them if they have ever seen that before; they will of course answer, No; you reply, neither have I, and I think you will confess that nobody else has ever seen it, and now no one shall ever see it again; saying which, you put the kernel into your mouth and eat it.