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in studying the elements of geometry, how much his recollection of the theorems was aided by the diagrams which are connected with them : and I have little doubt that the difficulty which students commonly find to remember the propositions of the fifth book of Euclid, arises chiefly from this, that the magnitudes to which they relate, are represented by straight lines, which do not make so strong an impression on the memory, as the figures which illustrate the propositions in the other five books.
This advantage, which the objects of sight naturally have over those of hearing, in the distinctness and the permanence of the impressions which they make on the memory, continues, and even increases, through life, in the case of the bulk of mankind; because their minds, being but little addicted to general and abstract disquisition, are habitually occupied, either with the immediate perception of such objects, or with speculations in which the conception of them is more or less involved; which speculations, so far as they relate to individual things and individual events, may be carried on with little or no assistance from language.
The case is different with the philosopher, whose habits of abstraction and generalization lay him continually under a necessity of employing words as an instrument of thought. Such babits cooperating with that inattention which he is apt to contract to things external, must have an obvious tendency to weaken the original powers of recollection and conception with respect to visible objects; and at the same time to strengthen the power of retaining propositions and reasonings expressed in language. The common system of education, too, by exercising the memory so much in the acquisition of grammar rules, and of passages from the ancient authors, contributes greatly, in the case of men of letters, to cultivate a capacity for retaining words.
It is surprising of what a degree of culture our power of retaining a succession, even of insignificant sounds, is susceptible. Instances sometimes occur, of men who are easily able to commit to memory a long poem composed in a language of which they are wholly ignorant; and I have myself known more than one instance of an individual who after having forgotten completely the classical studies of his childhood, was yet able to repeat with fluency long passages from Homer and Virgil, without annexing an idea to the words that he uttered.
This susceptibility of memory with respect to words is possessed by all men in a very remarkable degree in their early years, and is, indeed, necessary to enable them to acquire the use of language ; but unless it be carefully cultivated afterwards by constant exercise it gradually decays as we advance to maturity. The plan of education which is followed in this country, however imperfect in many respects, falls in happily with this arrangement of nature, and stores the mind richly, even in infancy, with intellectual treasures, which are to remain with it through life. The rules of grammar, which
comprehend systems, more or less perfect, of the principles of the dead languages, take a permanent hold of the memory, when the understanding is yet unable to comprehend their import; and the classical remains of antiquity, which, at the time we acquire them, do little more than furnish a gratification to the ear, supply us with inexhaustible sources of the most refined enjoyment; and, as our various powers gradually unfold themselves, are poured forth, without effort, from the memory, to delight the imagination, and to improve the heart. It cannot be doubted that a great variety of other articles of useful knowledge, particularly with respect to geographical and chronological details, might be communicated with advantage to children in the form of memorial lines. It is only in childhood that such details can be learned with facility; and if they were once acquired and rendered perfectly familiar to the mind, our riper years would be spared much of that painful and uninteresting labor, which is perpetually distracting our intellectual powers from those more important exertions for which, in their mature state, they seem to be destined.
This tendency of literary habits in general, and more particularly of philosophical pursuits, to exercise the thoughts about words, can scarcely fail to have some effect in weakening the powers of recollection and conception with respect to sensible objects ; and, in fact, I believe it will be found, that whatever advantage the philosopher may possess over men of little education, in stating general propositions and general reasonings, he is commonly inferior to them in point of minuteness and accuracy, when he attempts to describe any object which he has seen, or any event which he has witnessed ; supposing the curiosity of both, in such cases, to be interested in an equal degree. I acknowledge, indeed, that the undivided attention which men unaccustomed to reflection are able to give to the objects of their perceptions, is, in part, the cause of the liveliness and correctness of their conceptions.
With this diversity in the intellectual habits of cultivated and of uncultivated minds there is another variety of memory which seems to have some connection. In recognising visible objects the memory of one man proceeds on the general appearance, that of another attaches itself to some minute and distinguishing marks. A peasant knows the various kinds of trees from their general habits; a botanist, from those characteristical circumstances on which his classification proceeds. The last kind of memory is, I think, most common among literary men, and arises from their habit of recollecting by means of words. It is evidently much easier to express by a description a number of botanical marks, than the general habit of a tree ; and the same remark is applicable to other cases of a similar nature. But to whatever cause we ascribe it, there can be no doubt of the fact, that many individuals are to be found, and chiefly among men of letters, who, although they have no memory for the general appearances of objects, are yet able to retain with correctness, an immense number of technical discriminations.*
Each of these kinds of memory, has its peculiar advantages and inconveniences, which the dread of being tedious induces me to leave to the investigation of my readers.
Among the extraordinary exertions of memory recorded in History, it is worthy of observation, that many of them (more especially of those which are handed down to us from ancient times) relate to acquisitions of the most trifling nature; or at least to acquisitions which, in the present age, would be understood to reflect but little credit on the capacity of those who should consider the possession of them as a subject of vanity. In judging however, of such particulars, when they occur in the lives of eminent men, due allowances ought always to be made for the essential differences between the political institutions of the old world and those of modern Europe. Thus, when we are told of Themistocles, that he could call by their names all the citizens of Athens (whose number was 20,000 ;) and of Cyrus, that he knew the name of every soldier in bis army,t it ought to be recollected, that, contemptible as these
* The following facts, which throw considerable light on some of the observations in the text on the varieties of memory, are copied from the excellent Survey of Peebles-shire by the Reverend Charles Findlater.
“ About the beginning, or towards the middle of July, the lambs, intended for holding stock, are weaned; when they receive the artificial marks to distinguish to whom they belong ; which are the farmer's initials stamped upon their nose with a hot iron, provincially designed the birn; and also marks cut into the ears with a knife, designed lug-mark. Head-mark, or, in other words, the characteristic of individuality stamped by the hand of nature upon every individual of her numerous progeny, (and which we learn so readily to discern in all those species with which we are most familiarly conversant,) is, however, esteemed by every sheep-farmer as the most certain and unequivocal mark of the identity of a sheep :
a it is a mark with which no coincidence can take place (as in artificial ones) through either accident or purpose.”
The sequel of this passage is equally interesting, and, in my opinion, does great credit to the sagacity of the writer as a philosophical observer.
Something very similar to what Mr. Findlater has here remarked with respect to the faculty acquired by the shepherd of recognizing the individuals of his flock by head-mark, is observable in all men of business who have occasion to direct their attention habitually to the specific differences which mark the hand-writing of their various correspondents. In this case, too, as well as in the other, the general effect or character which the object presents to a practised eye, is a much inore infallible criterion of identity than a precise resemblance in a few prominent details ;-a resemblance, for instance, in the form of particular letters, or in those capricious flourishes of the pen by which inexperienced scribes attempt to give additional authenticity to their manuscripts." I remember a case of suspected forgery which fell under the cognizance of one of our courts of law, in which a reference was made of a doubtful signature ; first, to a set of engravers and writing-masters, and afterwards to the principal clerks in the different banking-houses of Edinburgh. The former (I was told) after a minute comparison of the signature in question, with other undoubted subscriptions of the alleged writer, pronounced it to be genuine. The latter without a moment's hesitation, asserted the contrary. I do not recollect the issue of the law-suit; but I have no doubt which of these two opinions was entitled to most weight in point of evidence.
+ This story of Cyrus is mentioned by Pliny, by Quinctilian, and by other Latin authors; but it is very justiy remarked by Muretus, that Xenophon, from whom alone these writers could derive any authentic information on the subject, only says that Cyrus remembered the names of the officers or captains who served under him ; zor ve' autür ixenórov.-Variarum Lectionum Lib.iii. Cap. 1.
acquisitions might now appear in men equally elevated by their rank, they were probably not altogether useless to the general of an ancient army, or to the chief of an ancient republic. The different state of manners prior to the invention of printing, and, in particular, the state of manners in ancient Greece and Rome, rendered the cultivation of memory an object of far greater importance to those who were destined for public life, than it is under any modern governments; and, accordingly, extraordinary endowments of this sort form a far more proininent feature in the characters of their illustrious writers and statesmen than they do in modern biography. Examples of this must immediately crowd on the recollection of every person at all conversant with the classics.
The facts with respect to memory, which I have chiefly in my eye at present, may be divided into two classes, according as they relate to occasional exertions of memory on particular subjects, or to the general mass of acquired information treasured up in the mind. Of the first kind are the intellectual feats ascribed to Cyneas, and 10 Hortensius. The former (we are told) when he came to Rome as ambassador from King Pyrrhus, saluted on the day after his arrival all the senators and persons of the equestrian order by their names; the latter, after sitting a whole day at a public sale, gave an account from memory in the evening of all the things sold, with the prices and the names of the purchasers; which account was found on examination to agree in every particular with what had been taken in writing by a notary. Nor will these anecdotes appear incredible, when compared with what Muretus himself saw at Padua, of a young Corsican, who, without stop or hesitation, recited thirty-six thousand names in the same order in which he had heard them, and afterwards beginning at the last, proceeded, in a contrary order, to the first.*
To the same class of facts belong (although they indicate also the strength of still higher faculties) those efforts which some individuals are able to make by mere force of attention and memory in the way of arithmetical computation. We are told by the celebrated Dr. Wallis of Oxford, that “ he himself could, in the dark, perform arithmetical operations, as multiplication, division, and extraction of roots to forty decimal places; particularly, that, in February 1671, he proposed to himself, by night in bed, (at the request of a foreigner,) a number of fifty-three places, and found its square root to twenty-seven places, and that, without ever writing down the number, he dictated the result from memory twenty days afterwards.” None of the facts, with respect to memory which I have met with in ancient authors, conveys to me so high an idea of the wonders which may be effected by a patient and steady concentration of our mental powers.t
Another example of intellectual vigor, not inferior to what Dr* Variarum Lectionum, Lib. iii. ibid. + Lowthrop's Abridgement of the Philosophical Transactions, Vol. III. 661.
Wallis has recorded of himself, occurred in a still more illustrious mathematician of the eighteenth century, the late Mr. Euler. The following particulars on this subject are extracted from his Eloge, read before the Academy of Sciences at Paris by M. de Condorcet; and, considering the unquestionable authenticity of the statement, they may be justly regarded as an important document in the History of the Human Mind. For the sake of some of my readers, it may be proper for me to premise, that this great man had the misfortune to lose his sight almost entirely at an early period of his very long life.
"A few years afterwards, Euler was overtaken by the calamity which he foresaw and dreaded, but, happily for himself and for the sciences, he was still able to distinguish large characters traced on a slate with chalk. His sons and his.pupils copied his calculations, and wrote, as he dictated, his scientific memoirs; from the immense number of which, combined with the singular genius frequently displayed in them, it would appear, that, in consequence of the absence of all external distraction, and of the new energy which this constrained recollection gave to his faculties, he gained more than he lost, both as to facility and means of labor, by his impaired vision.
“It is well known to all who have the slightest tincture of mathematics, that there exist in the modern analysis, (and Euler himself greatly multiplied their number) formulas of a common and almost daily application. These he had always present to his mind, and repeated in conversation with such a readiness and accuracy, that D'Alembert, who saw him at Berlin, spoke of his powers in this respect as scarcely credible to any but to eye-witnesses. His facility in carrying on arithmetical computations, without the aid of writing, was if possible still more astonishing. With the view of exercising his little grandson in the extraction of the square and cube roots, he is known to have formed to himself a table of the first six powers of all numbers from 1 to 100, and to have preserved it exactly in his memory. On one occasion, two of his pupils having calculated as far as the seventeenth term of a converging series, and their results differing one unit at the fiftieth figure, they communicated this circumstance to their master. Euler went over the whole calculation in his head, in order to decide the dispute ; and his decision was found, on examination, to be perfectly just.”
These facts, however, which relate to occasional exertions of memory on particulur subjects, do not lead to conclusions of so great practical utility, nor are they, perhaps, when duly weighed, so astonishing in themselves, as those which illustrate the comprehensiveness and retentiveness of which this faculty has been sometimes found susceptible, with respect to the general stock of human knowledge. A memorable or rather an extreme case of this sort is said to have occurred in “that prodigy of parts, Mr. Pascal,” of whom Mr. Locke tells us, “it was reported, that, till the decay of