410. The air is the slightest combination of the primary bodies, and stands in opposition with the two other elements, as more solid combustions. In this antagonism the air lays claim upon the other elements to analyse them; these, however, upon the air, to combine, and undergo more vivid combustion. 411. This antagonism is on a large scale an antagonism of periphery and centre, like the primary antagonism, by which planets and suns have withdrawn from each other. The tension of air with the other elements is called _Electricity_. The centroperipheric antagonism between the sun and the planet, between light and colour, represented in an elementary manner is electricity. 412. Sun and planet are electrically related to each other, and the circumrotation of the latter may be viewed as conditioned by the change of electrical poles. Colours also are only electrical productions. Light itself is similar to an electrical tension of the æther. 413. Electricity is an action of the periphery or limit and thus of the surface of the globe. The surface of the globe is, however, everywhere +-without centre. The principles of electricity are therefore eternally separated without having a middle point, as occurs in magnetism. The electrical poles live in eternal animosity, because they have no point of union. Such is then the essence of electricity. Electricity is therefore only a function of surfaces without any line. It clings only to the upper surface of the bodies, and does not penetrate into their thickness. It is only the tension of the surfaces of bodies against each other, of the apices of divided radii. 414. The air is the periphery, the _limit_ or boundary of the earth. Electricity is therefore the spirit of air. It is in its most active state in that stratum of air which is in contact with the earth, because there the limits are situated. Upon this lightning depends. 415. Electricity, as an aerial function, is terrestrial heat. Both are therefore conducted by the same rigid linear bodies and isolated by the same. The isolation of electricity coalesces with absence of form, or with the transition of denser bodies into air. 416. Electricity is an antagonism between air on the one side and water and earth upon the other. By these therefore two kinds of operation are posited in the air. 417. While electricity is the tension of air with the other elements, it is also the tension of the principles themselves of air. Electricity is a twofold character appertaining to the two principles of air. The tension of æther and of substance, thus the tension of fire repeated upon the two elementary bodies of air, is electricity. Electricity exists under two forms, as the electricity of the substance or body of fire, and as that of the planet. These two conditions are perhaps incorrectly named + E and-E, or positive and negative electricity.