PERFECT MEMORY OF THE SUBJECTIVE MIND. 41
Sir William Hamilton, in his " Lectures on Metaphysics," page 236, designates the phenomenon as " latent memory." He says:
" The evidence on this point shows that the mind frequently contains whole systems of knowledge, which, though in our normal state they have faded into absolute oblivion, may, in certain abnormal states as madness, febrile delirium, somnambulism, catalepsy, etc. flash out into luminous consciousness, and even throw into the shade of unconsciousness those other systems by which they had, for a long period, been eclipsed, and even extinguished. For example, there are cases in which the extinct memory of whole languages was suddenly restored ; and, what is even still more remarkable, in which the faculty was exhibited of accurately repeating, in known or unknown tongues, passages which were never within the grasp of conscious memory in the normal state."
Sir William then proceeds to quote, with approval, a few cases which illustrate the general principle. The first is on the authority of Dr. Rush, a celebrated American physician :
" The records of the wit and cunning of madmen," says the doctor, " are numerous in every country. Talents for eloquence, poetry, music, and painting, and uncommon ingenuity in several of the mechanical arts, are often evolved in this state of madness. A gentleman whom I attended in an hospital in the year 1810, often delighted as well as astonished the patients and officers of our hospital by his displays of oratory in preaching from a table in the hospital yard every Sunday. A female patient of mine who became insane, after parturition, in the year 1807, sang hymns and songs of her own composition during the latter stage of her illness, with a tone of voice so soft and pleasant that I hung upon it with delight every time I visited her. She had never discovered a talent for poetry or music in any previous part of her life. Two instances of a talent for drawing, evolved by madness, have occurred within my knowledge. And where is the hospital for mad people in which elegant and completely rigged ships and curious pieces of machinery have not been exhibited by persons who never discovered the least turn for a mechanical art previous to their derangement ?
" Sometimes we observe in mad people an unexpected resuscitation of knowledge ; hence we hear them describe past events, and speak in ancient or modern languages, or repeat long and