Rudolf Steiner felt the need for pioneers who, by advancing along the paths opened up by Goethe, would press forward into the realm of undiscovered phenomena on the upper border of nature, and this prompted him to give to those who were ready to listen various pointers towards new ways of experimental research. In so far as practical results have already been reached along these lines, they lie in the fields of biology and physiology (and of chemistry, in a certain respect) rather than in that of physics. Now, among the indications given in this latter field, and not yet worked out, there is one which deals with a way, unknown to-day, of influencing the spectrum by the magnet. The possibility of a magnetic influence on the spectrum is, in itself, not unknown to modern physics. It was the Dutchman, Zeeman, who first observed a change in the appearance of certain spectral lines as a result of light passing through a magnetic field. This discovery, however, is in two respects typical of modern science. The Zeeman effect consists in the splitting up of certain spectral lines into other lines - hence, of a breaking up of a whole into parts. And by seemingly providing a decisive confirmation of contemporary views concerning the electromagnetic nature of light, Zeeman's discovery has formed one of the milestones in the progress of modern physical thought - with the usual result that an enlargement of man's knowledge of the behaviour of natural forces has served to entangle his conception of nature still more deeply in illusion. Apart from the fact that our own way of combining observation and thought guards us against drawing theoretical conclusions from Zeeman's discovery, Rudolf Steiner's indication opens up the prospect of achieving quite practical results, opposite in character to those of the Zeeman effect. For in contradistinction to the use of a magnetic field for splitting the spectrum, Rudolf Steiner has made us aware of the possibility of uniting into a higher synthesis parts of the spectrum which normally appear in separated form. His indication points to nothing less than a leading over of the optically produced spectrum from its usual linear form, with two boundaries on either side, into a closed circular form, and of doing this by an adequate application - as yet undiscovered - of magnetic force. Further, according to his statement, the point where the two ends of the spectrum meet will prove to be a fountain-head of certain higher natural forces which otherwise are not directly accessible.