When a current of electricity passes through a fluid capable of decomposition the acids gather about the positive pole and the alkalies about the negative pole. We thus detect the exercise of separate activities on the part of the positive and negative electrical forces,--their polarization,--when we notice that alkalies and acids separate upon the application of electrical forces. Similar conditions exist in our bodies. They occur in the mucous and serous membranes; for the serous secretions react acid, the mucous ones, alkaline. The contrast, in anatomical structure, between the mucous and the serous membranes is due to the fact that they line the various organs, respectively, within and without. It also indicates an opposition in their electro-magnetic forces. These membranes cover, not only the large organs, but also the small ones, to the smallest muscular fibres. In this way an electro-magnetic contrast exists in every part of the body, and it is this opposition Of forces which keeps the vital machinery of the body in working order. Electro-magnetic attraction and resistance are the agencies which control metabolism and the action of the organs, so long as bodily strength and healthy blood are maintained. All internal and external stimuli are nothing more than electro-magnetic processes. Even our bodily temperature, as we commonly think of it under such conditions, resolves itself into electro-magnetic force or its product. Electricity, magnetism, light, and heat differ only in respect to vibration, and are in the final analysis one and the same. But since our bodies are not cold like the earth or, like its electric forces, vibrate slowly, but are warm and of quick vibration, we are sufficiently assured that they contain, not only the cold electro-magnetic forces, of slow vibration, but also those that are warm and vibrate rapidly. And thus, when a correct relation exists between positive and negative forces--that is to say, between the forces of electricity and magnetism, then only have we normal temperature, _then alone are we normally healthy_. When we come to enquire into the sources from which the body obtains these forces, there is little to be said. They are well known, can easily be traced, but to the keenest mind of scholarly research their source of origin is still an unturned page. Of things in the human economy which count, however, first in importance are food and breath; for in every atom of food we eat and every breath of air we breathe there are electrons which enter the body, there to be seized by the attraction of electro-magnetic action, stored away, and applied in vital processes. A source of vital energy, commonly known and little recognized, is the free, pure air, or, ether charged with the electrons of space.