The Wicked Marquis by E. Phillips Oppenheim

Sir Robert preferred to join his wife and sister-in-law in the drawing-room after luncheon. The Marquis, with a courteous word of invitation, led his remaining guest across the grey stone hall into the library beyond -- a sparsely furnished and yet imposing looking apartment, with its great tiers of books and austere book cases. On his way, he drew attention carelessly to one or two paintings by old masters, and pointed out a remarkable statue presented by a famous Italian sculptor to his great-grandfather and now counted amongst the world's treasures. His guest watched and observed in silence. There was nothing of the uncouth sight-seer about him, still less of the fulsome dilettante. They settled themselves in comfortable chairs in a pleasant corner of the apartment.

A footman served them with coffee, a second man handed cigars, and the butler himself carried a tray of liqueurs. The Marquis assumed an attitude of complete satisfaction with the world in general.