[46] Yule’s colour-blindness was one of the cases in which Dalton, the original investigator of this optical defect, took special interest. At a later date (1859) he sent Yule, through Professor Wilson, skeins of coloured silks to name. Yule’s elder brother Robert had the same peculiarity of sight, and it was also present in two earlier and two later generations of their mother’s family—making five generations in all. But in no case did it pass from parent to child, always passing in these examples, by a sort of Knight’s move, from uncle to nephew. Another peculiarity of Yule’s more difficult to describe was the instinctive association of certain architectural forms or images with the days of the week. He once, and once only (in 1843), met another person, a lady who was a perfect stranger, with the same peculiarity. About 1878–79 he contributed some notes on this obscure subject to one of the newspapers, in connection with the researches of Mr. Francis Galton, on Visualisation, but the particulars are not now accessible. [47] From Yule’s verses on her grave. [48] Lord Canning to Lady Clanricarde: Letter dated Barrackpoor, 19th Nov. 1861, 7 A.M., printed in _Two Noble Lives_, by A. J. C. Hare, and here reproduced by Mr. Hare’s permission. [49] Lord Canning’s letter to Lady Clanricarde. He gave to Yule Lady Canning’s own silver drinking-cup, which she had constantly used. It is carefully treasured, with other Canning and Dalhousie relics, by the present writer. [50] Many years later Yule wrote of Lord Canning as follows: “He had his defects, no doubt. He had not at first that entire grasp of the situation that was wanted at such a time of crisis. But there is a virtue which in these days seems unknown to Parliamentary statesmen in England—Magnanimity. Lord Canning was an English statesman, and he was surpassingly magnanimous. There is another virtue which in Holy Writ is taken as the type and sum of all righteousness—Justice—and he was eminently just. The misuse of special powers granted early in the Mutiny called for Lord Canning’s interference, and the consequence was a flood of savage abuse; the violence and bitterness of which it is now hard to realise.” (_Quarterly Review_, April, 1883, p. 306.) [51] During the next ten years Yule continued to visit London annually for two or three months in the spring or early summer. [52] Now in the writer’s possession. They appear in the well-known portrait of Lord Canning reading a despatch. [53] Lord Canning’s recommendation had been mislaid, and the India Office was disposed to ignore it. It was Lord Canning’s old friend and Eton chum, Lord Granville, who obtained this tardy justice for Yule, instigated thereto by that most faithful friend, Sir Roderick Murchison.