Clearly, then, in the case of electrical polarity we encounter a certain form of gravity-bound levity, and this in a twofold way. Owing to the contrasting nature of the two bodies involved in the process, the coupling of gravity and levity is a polar one on both sides. The electrical polarity thus turns out to be itself of the nature of a secondary polarity.

The same is true of the phenomena bound up with radioactivity, which were discovered in direct consequence of Crookes's work. We know that the naturally radioactive elements are all in the group of those with the highest atomic weight. This fact, seen together with the characteristics of radioactivity, tells us that in such elements gravity has so far got the upper hand of levity that the physical substance is unable to persist as a spatially extended, coherent unit. It therefore falls asunder, with the liberated levity drawn into the process of dispersion. Seen thus, radioactivity becomes a symptom of the earth's old age.

Although, from our view-point, magnetism represents only one 'half of a phenomenon, the other half of which is heat, we must not forget that it is itself a bipolar force. Thus, despite its apparent relation to gravity it does not represent, as gravity does, one pole of a primary polarity, with heat as the other pole. Rather must it carry certain qualities of levity which, together with those of gravity, appear in a polarically opposite manner at its two poles. (Details of this will be shown later when we come to investigate the individual qualities of the two poles of magnetism and electricity.) Hence the heat that forms the counterpart to magnetism cannot be pure levity either. As the result of a certain coupling with gravity, it too has somehow remained polarically split.

At this point in our discussion it is possible to raise, without risk of confusing the issue, the question of the distribution of the two electric forces over the pairs of substances concerned in the generation of electricity both by friction and in the galvanic way. This distribution seems to contradict the picture to which the foregoing observations have led us, for in both instances the 'sulphurous' substances (resin in one, the nobler metals in the other) become bearers of negative electricity; while the 'saline' substances (glass and the corrosive metals) carry positive electricity. Such a criss-crossing of the poles-surprising as it seems at first sight - is not new to us. We have met it in the distribution of function of the plant's organs of propagation, and we shall meet a further instance of it when studying the function of the human eye. Future investigation will have to find the principle common to all instances in nature where such an interchange of the poles prevails.

We follow Goethe's line when, in order to answer the question, 'What is electricity?' we first ask, 'How does electricity arise?' Instead of starting with phenomena produced by electricity when it is already in action, and deriving from them a hypothetical picture, we begin by observing the processes to which electricity owes its appearance. Since there is significance in the historical order in which facts of nature have come to man's knowledge in the past, we choose as our starting-point, among the various modes of generating electricity, the one through which the existence of an electric force first became known. This is the rousing of the electric state in a body by rubbing it with another body of different material composition. Originally, amber was rubbed with wool or fur.

Two more recently discovered means of evoking the electric condition in a piece of matter confirm this picture. They are the so-called piezo-electricity and pyro-electricity. Both signify the occurrence of the electrical polarity at the two ends of an asymmetrically built (hemimorphous) crystal, as the result of changing the crystal's spatial condition. In piezo-electricity the change consists in a diminution of the crystal's volume through pressure; in pyro-electricity, in an increase of the crystal volume by raising its temperature. The asymmetry of the crystal, due to a one-sided working of the forces of crystallization, plays the same role here as does the alchemic opposition between the two bodies used for the production of frictional electricity.

Before entering into a discussion of the question, which naturally arises at this point, as to how levity and gravity by their two possible ways of interaction - 'sulphurous' or 'saline' - determine the properties of so-called positive and negative electricity, we shall first study the third mode of generating electricity, namely, by electromagnetic induction. Along this way we shall arrive at a picture of the magnetic force which corresponds to the one already obtained of electricity. This will then lead us to a joint study of the nature of electric polarity and magnetic polarity.

This can easily be seen by considering the following. Unlike the levity-gravity polarity, in which one pole is peripheral and the other point-centred, both Doles of the electrical polarity are point-centred; both are located in physical space, and thereby determine a definite direction within this space. It is this direction which remains a characteristic of both the magnetic and the thermal fields. The direction of the thermal field as much as that of the magnetic is determined by its having as its axis the conductor joining the poles of the antecedent electrical field. Both fields supplement each other in that the thermal radiation forms the radii which belong to the circular magnetic lines-of-force surrounding the conductor.³

While the electric field arising round an electrified piece of matter does not allow any recognition of the absolute characteristics of the two opposing electrical forces, we do find them revealed by the distribution of electricity in the human body. Something similar holds good for magnetism. Only, to find the phenomena from which to read the absolute characteristics of the two sides of the magnetic polarity, we must not turn to the body of man but to that of the earth, one of whose characteristics it is to be as much the bearer of a magnetic field as of gravitational and levitational fields. There is significance in the fact that even to-day, when the tendency prevails to look for causes of natural phenomena not in the macrocosmic expanse, but in the microscopic confines of space, the two poles of magnetism are named after the magnetic poles of the earth. It indicates the degree to which man's feeling instinctively relates magnetism to the earth as a whole.

By picturing this process in our mind we become aware of a certain kinship of electricity with fire, since for ages the only known way of kindling fire was through friction. We notice that in both cases man had to resort to the will-power invested in his limbs for setting in motion two pieces of matter, so that, by overcoming their resistance to this motion, he released from them a certain force which he could utilize as a supplement to his own will. The similarity of the two processes may be taken as a sign that heat and electricity are related to each other in a certain way, the one being in some sense a metamorphosis of the other. Our first task, therefore, will be to try to understand how it is that friction causes heat to appear in manifest form.