Ev. Thanks to your own memory, Ida, for these incidents. That the possession of the faculty of this impression of memory can be demonstrated, we might doubt, were verbal description only employed; but when we see the artist trace the features of a person long lost to us from memory, we know that such ideas existed, and were then re-excited in his mind.
The power of the intellect in retaining these impressions is wonderful. Cyrus is said to have remembered the names of all his soldiers, and Themistocles those of two thousand Athenians.
We have records from Seneca and others, that some will remember, after one perusal or hearing, very long poems; and even have repeated, word for word, the unconnected jumble of a newspaper. Pascal, as we are told by Locke, never forgot anything. Almost equally retentive was the memory of my excellent teacher, Sir Astley Cooper, and hence his nearly unexampled accumulation of facts. The memory of Ben Jonson was retentive to perfection, until the fortieth year of his age. In his youth, he could repeat an entire volume after its perusal; nay, even the whole of his own works, or as he quaintly writes, “All that ever I made.” We know that Bloomfield composed his “Farmer’s Boy” in the bustle of a shoe manufactory, and wrote from his memory.
Astr. I have heard that the particles of the body are constantly changing: if so, how can memory exist in the brain?
Ev. The answer is easy. Because particles of exact similarity are deposited as others are removed. The parts thus regenerated, of whatever structure they may be, still being identical and unchanged in function.
If the dream be an inspiration, Astrophel, it is like “a spirit of the past,” and does not “speak like sybils of the future.”
But ere I offer some analogies of waking memory, in illustration of the causes of the dream, I must again fatigue you by a glance at the physiology of memory; the origin or mode of impression of a sense, and the mode of recurrence of such impression, i.e. the excitement of the dream.
Aristotle has asserted that senses cannot receive material objects, but only their species, or ειδωλον; and Mr. Locke entertained the same idea. For this effect, however, matter must have touched a sense, and its impression, as Baron Haller thought, must have been mechanical. For instance, the rays emanating from a body, and impinging on the retina, or an undulation of sound on the labyrinth of the ear, stamp an image on the brain, by which, (in accordance with a prior observation on illusion,) some minute change is inevitably effected; some minute cerebral atoms are displaced.
If you propose to me that curious physiological question,—in what consists the function of a nerve—in oscillation, or in undulation of a fluid, in electricity, or in magnetism? or how the nerve carries this impression to the brain? or if you desire me to meet the subtle objection, which Dr. Reid advanced against the opinion of Aristotle and of the more modern psychologists,—I might weary you with conjectures like those of Newton and Hartley, that some ethereal fluid was, by the impulse of peculiar stimulus to its nerve, the cause of the senses; or that the mental phenomena are an imparting, or influence of the immaterial soul by corporeal vibration; or that dreams are “motions of fibres:” and at length, with humility confess this to be a mystery we cannot yet fathom. And this I do the more willingly, as it may prove my devotion to the proper limits of our study; moreover, the question itself is not essential to my argument.
Yet it is certain that external impressions of every object or subject, reach the brain through the medium of a nerve; and when the same fibrils of those nerves, or that spot of brain on which the original image rested, are again irritated by their proper stimulus, or by the same or a similar body, an association is produced, and memory is the result.