though they had something of our diffusion of electric sense, had also in the back of their necks a localised sense that responded to the faintest magnetic influence and measured roughly its amount and its changes in kind and degree. The delicate nerve-centre there, which might have been the remains of a backward-looking eye, had developed with them into a most sensitive collector of electric vibration in the air or in any section of matter; and in every atom, whether organic or inorganic, they declared there was ever some electric wave motion; in some it was too faint to affect their firla or electric sense, but then their delicate instruments for magnifying it, like their mirlans, made it manifest to their senses and definable. It was to my general feeling of magnetism what the muscular sense in my fingers was to my diffused sense of touch. It had taken many generations to develop, and in their children it never appeared till they had reached the close of youth; but part of their education was directed towards making it more sensitive and useful as a power for measuring force. A former generation of their medical investigators had long noticed and studied the effect of the concentration of will-power through the eye upon the back of the neck of one who sat in front of them; although the patient could tell nothing by means of his five senses of such an effort being made behind him, he generally turned round. Experiment after experiment proved that there was a force communicated through the intervening space to some sensitive spot on the back of the head or neck, and they knew that relics existed of what seemed once to have been an eye in that region. They came to the conclusion that this must have a closer connection with the higher brain-centres than any part of the body except the eye, and bent their whole attention upon its nature. They soon defined it as a localised electric sense and by practice made it as keen at least as the sense of touch in the fingers. They were at last able to define the direction of an electric influence and to note its changes of force, and, after several generations, their firla, as they called it, came to rank next to sight and equal to hearing in the analysis and investigation of the phenomena of the universe.