The fact that modern science has long ceased to be a 'natural' science is something which has begun to dawn upon the modern scientific researcher himself. What has thus come to him as a question finds a definite answer in the picture of electricity we have been able to develop. It is again Eddington who has drawn attention particularly to this question: see the chapter, 'Discovery or Manufacture?' in his Philosophy of Physical Science. It will be appropriate at this point to recall his remarks, for they bear not only on the outcome of our own present discussion, but also, as the next chapter will show, on the further course of our studies. Eddington starts by asking: 'When Lord Rutherford showed us the atomic nucleus, did he find it or did he make it?' Whichever answer we give, Eddington goes on to say, makes no difference to our admiration for Rutherford himself. But it makes all the difference to our ideas on the structure of the physical universe. To make clear where the modern physicist stands in this respect, Eddington uses a striking comparison. If a sculptor were to point in our presence to a raw block of marble saying that the form of a human head was lying hidden in the block, 'all our rational instinct would be roused against such an anthropomorphic speculation'. For it is inconceivable to us that nature should have placed such a form inside the block. Roused by our objection, the artist proceeds to verify his theory experimentally - 'with quite rudimentary apparatus, too: merely using a chisel to separate the form for our inspection, he triumphantly proves his theory.' 'Was it in this way', Eddington asks, 'that Rutherford rendered concrete the nucleus which his scientific imagination had created?' One thing is certain: 'In every physical laboratory we see ingeniously devised tools for executing the work of sculpture, according to the designs of the theoretical physicist. Sometimes the tool slips and carves off an odd-shaped form which he had not expected. Then we have a new experimental discovery,' To this analogy Eddington adds the following even more drastic one: 'Procrustes, you will remember,' he says, 'stretched or chopped down his guests to fit the bed he constructed. But perhaps you have not heard the rest of the story. He measured them up before they left the next morning, and wrote a learned paper On the Uniformity of Stature of Travellers for the Anthropological Society of Attica.' * Besides yielding a definite answer to the question of how far the seemingly discovered facts of science are manufactured facts, our newly won insight into the nature of the electric and magnetic polarties throws light also on the possibility of so handling both that their application will lead no longer to a cancellation, but to a true continuation, of nature's own creative deeds. An example of this will appear in the next part of our studies, devoted to observations in the field of optics.