The Great Polyptych had not yet reached completion when, on the 18th of September 1426 Hubert van Eyck passed away after a painful illness. How much of the work remained to be accomplished none can tell with any hope of approach to certainty. A whole volume would not suffice for a critical examination of the mass of contending theories that for the best part of a century has been squandered in the endeavour to allocate to the two brothers their respective shares in the execution of the picture. Remember that it had already been some ten years in the making, and that, although it did not receive its final touches from the brush of John van Eyck until 1432, nearly six years after his brother's death, this period of John's life, as we shall presently discover, was too fully occupied in the service of Duke Philip of Burgundy to have allowed of his spending any considerable proportion of it in the task of completion. Remembering also that John's art had been closely modelled on that of his brother, that none better comprehended his ideals or was more intimately acquainted with the working out of his conceptions, mindful, moreover, of the deep veneration in which he held his master's genius, we must suppose that he realised the obligation of conscientiously adhering to the art and technique of the picture as he found it, any obtruding originality in violation of which would have amounted almost to sacrilege: all this further enhances the difficulty of differentiating between the work of the two painters. Indeed, if so minded, the reader is probably as well equipped as the writer to solve the puzzle. [Illustration: PLATE V.--JOHN ARNOLFINI AND JOAN CENANI, HIS WIFE (By John van Eyck) An incomparable example of the Master's varied gifts, and a valuable study of contemporary dress and domestic furniture. Joan Cenani is presumed to have been a younger sister of Margaret van Eyck, with whose portrait, reproduced in Plate VII., it should be compared. The carved frame of the mirror on the far wall enshrines ten small medallions, exquisite miniatures representing the Agony in the Garden, the Betrayal and St. Peter's Assault on Malchus, Christ led before Pilate, the Scourging at the Pillar, the Carrying of the Cross, Calvary, the Deposition, the Entombment, the Descent into Limbo, and the Resurrection. On the wall above the mirror we read the precise statement, "Iohannes de eyck fuit hic 1434." No. 186 in the National Gallery, London. See page 67.]