Archimedes, Galileo, and Newton co-operated in the discovery of immutable laws, and thereby revealed to mortal man morsels of the _eternal truth_. Oerstedt, a hundred years ago, discovered a morsel of the eternal truth when he discovered the magnetic force which is produced by the motion of electricity. Discoveries of immortal things and of the immutable laws which direct the mission of their immortal existence are themselves immortal. Their discoverers are, and deserve to be, immortal. Tyndall and Maxwell were the first to show me that Faraday occupied a distinguished place among such immortals as Archimedes, Galileo, Newton, and Oerstedt. The closing sentence of Maxwell’s biographical sketch of Faraday, in vol. VIII of _Nature_, referred to above, reads as follows: We are probably ignorant even of the name of the science which will develop out of the materials we are now collecting, when the great philosopher next after Faraday makes his appearance. To me these prophetic words indicated that Maxwell had something in his mind which was not explicitly expressed in Faraday’s discoveries, but which enabled Maxwell to speak like a prophet. The words of a prophet are not always easy to understand. I discovered later that, when the world with the aid of the Hertzian experiments had caught Maxwell’s meaning, then a new and wonderful epoch in the history of the physical sciences was inaugurated. Its end is not yet in sight. This inauguration I witnessed during my student days in Berlin. It is, I believe, of considerable interest to record here how the scientific world, as I saw it at that time, appeared to be preparing to receive the great revelation which was delivered to it on that historic inauguration day in 1887. My communion with Faraday on the island of Arran began my own preparation for this inauguration day by developing gradually in my mind new physical concepts, which I discovered later to be fundamental physical concepts in the modern views of physics. Long before I had finished my reading of Faraday’s “Experimental Researches in Electricity,” I began to understand why Tyndall, referring to them, said: “Read them; their story is just as new and as stirring to-day as it was when these volumes were first printed. They will help you much to interpret Maxwell.” The same statement is true to-day, and therefore I proceed now, with much trepidation, to tell a part at least of that story as briefly as I can, in order to describe, even if it be quite inadequately, Faraday’s relation to the present great epoch of modern physics, the epoch of the electromagnetic view not only of _light_ but also of _matter_.