Gregory’s appearance was most noticeable. He was of great proportions, obese, slouching and loosely hung together. In later years his body was a great burden to him, but the mind kept the mastery. He was, like his father, a keen student of language, and would wile away many of the weary hours of forced inaction by the study of foreign tongues. French and German were to him as familiar as English. With a microscope, too, he did beautiful work, and was in his day, the greatest authority on the Diatomaceae. The slides which he made of these microscopic water-plants with their sculptured valves, were another resource of his declining years. He presented valuable memoirs on this subject to the Royal Society of Edinburgh, of which he was a member. Professor William Gregory died in Edinburgh in April 1858, and was honoured with a public funeral. He was succeeded in the university by Dr Lyon Playfair (afterwards Lord Playfair) who had contested the chair unsuccessfully at the time of Gregory’s appointment. William Gregory was survived by an only son, who was called after his father’s far-famed friend, James Liebig Gregory. Duncan Farquharson Gregory was considerably younger than his brother the Professor of Chemistry, and was not at all like him in personal appearance. His face was a beautiful one, fine, pale, bearing on it already in this life some of the light and joyousness that often mark out for especial love those who are to pass quickly from this earth. His hair, which was thick and curling, fell more about his brow than is usual, and his eyes like dark lamps illuminated his features. When he was hardly more than a baby, his father used fondly to predict distinction for him. ‘He had pleasure in conversing with him as with an equal on subjects of History and Geography,’ so Mr Ellis wrote, and this when the boy was not more than six, for his father died before he had left the nursery. He was a great inventor of games for himself, and made an orrery with his busy little hands, on which he would send the planets spinning round in their orbits. Till he was nine years old he was taught entirely by his mother, who was quite as attractive to her children as she had ever been in society, and for whom Duncan had always a peculiar reverence and affection. He passed out of her hands into the care of a tutor, and then was sent to the Edinburgh Academy. From school he went abroad to Geneva, where his mother and sisters were spending a winter, and on his return he attended classes at the University of Edinburgh. In mathematics he made astonishing strides, under Professor Wallace, and those who saw the master and pupil together in Cambridge in after days, said that the old man’s pride in his pupil’s success never diminished.