I may, therefore, claim that he was the first person to deal in a scientific spirit with the subject which I have chosen for this lecture, the ‘Growth of a Crystal.’ Three years before I came back to Oxford—on May 16th, 1893, the subject of crystal structure had been treated in the second BOYLE Lecture in a most original and masterly manner by no less a person than LORD KELVIN. I well remember that Lecture, at which I had the good fortune to be present; and to one who was already interested in crystals it was a wonderfully illuminating and inspiring address. On that occasion my venerable predecessor and teacher, Professor STORY MASKELYNE, conducted LORD KELVIN to the lecture table.[1] [Footnote 1: It is with the deepest regret that I add that my old friend and revered teacher died on the very day on which these words were spoken.—H. A. M.] At that time, however, there was no laboratory in Oxford for mineralogical and crystallographical research; the Professor only had a lecture-room, he did not reside in Oxford, and his scientific work was necessarily carried on elsewhere. To-day I am more fortunate in being able to draw upon the resources of the well-equipped laboratory of my successor, and former pupil, Professor BOWMAN, and upon his still more valuable personal assistance and that of Mr. BARKER; so that, though I only have to deal with ideas that are simple compared with those which issued with fiery vigour from the fertile brain of the BOYLE Lecturer of 1893, I have a better opportunity of showing to an Oxford audience to-day the actual things of which I am speaking, and may help to make my meaning clear to those who cannot know much from personal experience concerning the growth of crystals.[2] When I delivered my own inaugural lecture I had no means of making visible to an audience the astonishing features of crystal growth. Beautiful effects may easily be witnessed by anyone with a few drops of common solution and a magnifying glass, yet I believe that they are witnessed by comparatively few persons. [Footnote 2: This lecture was beautifully illustrated by excellent slides showing the actual _growth_ of crystals.—ED.]