in the brain of A, the suggestor, and the analogous physical change in the
brain of B, the recipient of the suggestion. Between these two physical
events there must exist a train of physical causes. * * * It is
unscientific to call in the aid of mysterious agencies, when with every
fresh advance in knowledge it is shown that either vibrations have powers
and attributes abundantly able to any demand--even the transmission of
thought.

"It is supposed by some physiologists that the essential cells of nerves
do not actually touch, but are separated by a narrow gap which widens in
sleep while it narrows almost to extinction during mental activity. This
condition is so singularly like a Branly or Lodge coherer (a device which
led to the discovery of wireless telegraphy) as to suggest a further
analogy. The structure of brain and nerve being similar, it is conceivable
that there may be present masses of such nerve coherers in the brain,
whose special function it may be to receive impulses brought from without,
through the connecting sequence of ether waves of appropriate order of
magnitude.

"Roentgen has familiarized us with an order of vibrations of extreme
minuteness as compared with the smallest waves with which we have hitherto
been acquainted: and there is no reason to suppose that we have here
reached the limit of frequency. It is known that the action of thought is
accompanied by certain molecular movements in the brain, and here we have
physical vibrations capable from their extreme minuteness of acting direct
upon individual molecules, while their rapidity approaches that of
internal and external movements of the atoms themselves. A formidable
range of phenomena must be scientifically sifted before we effectually
grasp a faculty so strange, so bewildering, and for ages so inscrutable,
as the direct action of mind upon mind.