A generous colleague from the Ohio State University has lately written to ask me whether, when writing The Finger: A Handbook, I had ever come across any references to marginalia having been inscribed with the reader’s thumb-nail. In The Rivals (1:2) Richard Brinsley Sheridan has Lydia Languish refer to Lady Slattern, who “has a most observing thumb; and…cherishes her nails for the convenience of making marginal notes.” He goes on to say, quite correctly, that there is a similar observation made in Pushkin’s Eugene Onegin, and asks me whether I know if the practice in fact ever existed. Alas, I had never come across either of these intriguing references. Presumably the idea was that Lady Slattern’s thumbnail was maintained in such a way—even pared down to a sharp point—so as not merely to mark the passage more effectively with an indentation, à la manicule (above) but to annotate busily also, which might conceivably require doing to it what one does with a sharp knife to the tip of a quill. Tatiana learns much about Onegin in his library, specifically from the marks of his pencil and thumbnail in the margins of various books, which implies a distinction there between pencilled notes and indented marks and/or underlinings done with his thumb-nail. I very much doubt if the quill-sharpening step was ever undertaken, so the joke in Sheridan must be about officiousness, or maybe inquisitiveness, or even interference, in other words making of Lady Slattern some sort of equivalent of P. G. Wodehouse’s glorious creation “the efficient Baxter.” I am guessing. I daresay the phenomenon may relate, however approximately, to the concept of “thumb-nail sketch,” although the O.E.D. (“thumb-nail…2. transf. A drawing or sketch of the size of the thumb-nail; hence fig. a brief word-picture. Chiefly attrib., as thumb-nail sketch”) admits no possibility that such a sketch might actually have been produced with the aid of the thumbnail. This would not be the first time that the O.E.D. ever overlooked some forgotten shred of social usage. We know, for example, that eighteenth-century French gentlemen grew the nail of their little finger for the specific purpose of scratching discreetly at doors, to distinguish that refined gesture from the crude knocking of factors, salespeople, or servants. We also know that J. M. W. Turner cultivated a long fingernail as a convenient tool for scraping, chiefly on paper through watercolour, but that is quite a different matter and I am not aware that he ever wrote with it.