I need not insist on the gulf that separates crystallography, a true science, from crystallogy, its base mercantile application. To the one, as was but right, a chair was attached; a chair founded by Z. Leizler the philanthropist, before his flight, and now occupied by the aged figure of the de Bohun. The other was thought hardly worth a Readership at £600 a year, and only under secret threats had that wealthy college, St. Filbert's, been persuaded by certain City men whom B. Leader in his turn had threatened, to cough up. It took its revenge by admitting B. Leader to its high table, and refusing to elect him a Fellow. He it was who, waging secret war upon university caste, dug his revengeful fangs into the Professor's naked soul. He it was who spotted with relentless eye all the misprints in the Professor's papers, and denounced them as enormities of ignorance in the _British Crystallographic Review_, with which is combined the _Crystal Gazetteer_ and _Bulletin_. He it was who exploded de Bohun's ancient German doctrines with the recent research of horrid Dagoes, and exposed it to derision whenever he lectured to a class of more than a dozen; for his department being mixed up with commerce, there was money in it, and a few undergraduates on the scent of the same; not so the Professor's department. Now two, now one student, sought the well of learning, and sometimes none. On the other hand, Professor de Bohun could--and did--nourish a burning happiness in his heart to remember that the infamous B. Leader was of no lineage and had no private income at all. Nay, worse; an accent--almost a twang. But alas! for the alloyed happiness of risen man, in whom the highest have something in them of the ape, (Poggles _General View_, Vol. II, Ch. XXII, p. 222). B. Leader himself nourished a secret burning joy in his heart; for he had found out--what the great thought was peculiar to their own circle--the dreadful story of William de Bohun and the Mullingar Diamond. Because he loved crystals--not because he loved wealth: because the Mullingar Diamond was the largest of its yellow kind in the world, and had a flaw which was confidently reported to be due--incredible!--to a bubble, William de Bohun had, eight years before, while stopping at the Abbey as an honoured guest, pinched the Mullingar Diamond--not for a permanency, but to make a close examination of the incredible bubble. He had returned it, but already his action had got known, and some people were cold to him. The less instructed among the great whispered that he had been a famous thief in youth; the more instructed believed that his profound science had produced a momentary lapse. The Family knew, but had long forgiven him; indeed, there was nothing to forgive--they said.