Thus far the instances I have related seem to resolve themselves into cases of simple clairvoyance, or second sight in sleep, although, in using these words, I am very far from meaning to imply that I explain the thing, or unveil its mystery. The theory above alluded to, seems as yet, the only one applicable to the facts, namely, that the senses, being placed in a negative and passive state, the universal sense of the immortal spirit within, which sees, and hears, and knows, or rather, in one word, _perceives_, without organs, becomes more or less free to work unclogged. That the soul is a mirror in which the spirit sees all things reflected, is a modification of this theory; but I confess I find myself unable to attach any idea to this latter form of expression. Another view, which I have heard suggested by an eminent person, is, that if it be true, as maintained by Dr. Wigan, and some other physiologists, that our brains are double, it is possible that a polarity may exist between the two sides, by means of which the negative side may, under certain circumstances, become a mirror to the positive. It seems difficult to reconcile this notion with the fact, that these perceptions occur most frequently when the brain is asleep. How far the sleep is perfect and general, however, we can never know; and of course, when the powers of speech and locomotion continue to be exercised, we are aware that it is only partial, in a more or less degree. In the case of magnetic sleepers, observation shows us, that the auditory nerves are aroused by being addressed, and fall asleep again as soon as they are left undisturbed. In most cases of natural sleep, the same process, if the voice were heard at all, would disperse sleep altogether; and it must be remembered that, as Dr. Holland says, sleep is a fluctuating condition, varying from one moment to another, and this allowance must be made when considering magnetic sleep also.