In one way, of course, these facts might be explicable on the supposition that Plattner has undertaken an elaborate mystification, on the strength of his heart’s displacement. Photographs may be fudged, and left-handedness imitated. But the character of the man does not lend itself to any such theory. He is quiet, practical, unobtrusive, and thoroughly sane, from the Nordau standpoint. He likes beer, and smokes moderately, takes walking exercise daily, and has a healthily high estimate of the value of his teaching. He has a good but untrained tenor voice, and takes a pleasure in singing airs of a popular and cheerful character. He is fond, but not morbidly fond, of reading,—chiefly fiction pervaded with a vaguely pious optimism,—sleeps well, and rarely dreams. He is, in fact, the very last person to evolve a fantastic fable. Indeed, so far from forcing this story upon the world, he has been singularly reticent on the matter. He meets enquirers with a certain engaging—bashfulness is almost the word, that disarms the most suspicious. He seems genuinely ashamed that anything so unusual has occurred to him. It is to be regretted that Plattner’s aversion to the idea of post-mortem dissection may postpone, perhaps for ever, the positive proof that his entire body has had its left and right sides transposed. Upon that fact mainly the credibility of his story hangs. There is no way of taking a man and moving him about _in space_, as ordinary people understand space, that will result in our changing his sides. Whatever you do, his right is still his right, his left his left. You can do that with a perfectly thin and flat thing, of course. If you were to cut a figure out of paper, any figure with a right and left side, you could change its sides simply by lifting it up and turning it over. But with a solid it is different. Mathematical theorists tell us that the only way in which the right and left sides of a solid body can be changed is by taking that body clean out of space as we know it,—taking it out of ordinary existence, that is, and turning it somewhere outside space. This is a little abstruse, no doubt, but any one with any knowledge of mathematical theory will assure the reader of its truth. To put the thing in technical language, the curious inversion of Plattner’s right and left sides is proof that he has moved out of our space into what is called the Fourth Dimension, and that he has returned again to our world. Unless we choose to consider ourselves the victims of an elaborate and motiveless fabrication, we are almost bound to believe that this has occurred.