The first thing that strikes us, in looking over Doctor Franklin's works, is the variety of his observations upon different subjects. We might imagine, that a very tenacious and powerful memory was necessary to register all these; but Dr. Franklin informs us, that it was his constant practice to note down every hint as it occurred to him: he urges his friends to do the same; he observes, that there is scarcely a day passes without our hearing or seeing something which, if properly attended to, might lead to useful discoveries. By thus committing his ideas to writing, his mind was left at liberty to think. No extraordinary effort of memory was, even upon the greatest occasions, requisite. A friend wrote to him to inquire how he was led to his great discovery of the identity of lightning and electricity; and how he first came to think of drawing down lightning from the clouds. Dr. Franklin replies, that he could not answer better than by giving an extract from the minutes he used to keep of the experiments he made, with memorandums of such as he purposed to make, the reasons for making them, and the observations that rose upon them. By this extract, says Dr. Franklin, you will see that the thought was not so much an out of the way one, but that it might have occurred to any electrician.[50]
When the ideas are arranged in clear order, as we see them in this note, the analogy or induction to which Dr. Franklin was led, appears easy. Why, then, had it never been made by any other person? Numbers of ingenious men were at this time intent upon electricity. The ideas which were necessary to this discovery, were not numerous or complicated. We may remark, that one analogy connecting these observations together, they are more easily recollected; and their being written down for a particular purpose, on which Dr. Franklin's mind was intent, must have made it still easier to him to retain them.
The degree of memory he was forced to employ, is thus reduced to a portion in which few people are defective. Now, let us suppose, that Dr. Franklin, at the time he wrote his memorandum, had fully in his recollection every previous experiment that had ever been tried on electricity; and not only these, but the theories, names, ages, and private history, of all the men who had tried these experiments; of what advantage would this have been to him? He must have excluded all these impertinent ideas successively as they rose before him, and he must have selected the fifteen useful observations, which we have mentioned, from this troublesome multitude. The chance in such a selection would have been against him; the time employed in the examination and rejection of all the unnecessary recollections, would have been absolutely wasted.
We must wish that it were in our power, when we make observations upon nature, or when we read the reflections of others, to arrange our thoughts so as to be ready when we want to reason or invent. When cards are dealt to us, we can sort our hand according to the known probabilities of the game, and a new arrangement is easily made when we hear what is trumps.
In collecting and sorting observations, Dr. Franklin particularly excelled; therefore we may safely continue to take him for our example. Wherever he happened to be, in a boat, in a mine, in a printer's shop, in a crowded city, or in the country, in Europe or America, he displays the same activity of observation. When any thing, however trifling, struck him which he could not account for, he never rested till he had traced the effect to its cause. Thus, after having made one remark, he had fresh motive to collect facts, either to confirm or refute an hypothesis; his observations tending consequently to some determinate purpose, they were arranged in the moment they were made, in the most commodious manner, both for his memory and invention; they were arranged either according to their obvious analogies, or their relation to each other as cause and effect. He had two useful methods of judging of the value of his own ideas; he either considered how they could be immediately applied to practical improvements in the arts, or how they could lead to the solution of any of the great problems in science. Here we must again observe, that judgment saved the labour of memory. A person, who sets about to collect facts at random, is little better than a magpie, who picks up and lays by any odd bits of money he can light upon, without knowing their use.
Miscellaneous observations, which are made by those who have no philosophy, may accidentally lead to something useful; but here we admire the good fortune, and not the genius, of the individuals who make such discoveries: these are prizes drawn from the lottery of science, which ought not to seduce us from the paths of sober industry. How long may an observation, fortunately made, continue to be useless to mankind, merely because it has not been reasoned upon! The trifling observation, that a straight stick appears bent in water, was made many hundred years before the reason of that appearance was discovered! The invention of the telescope might have been made by any person who could have pursued this slight observation through all its consequences.
Having now defined, or rather described, what we mean by a good memory, we may consider how the memory should be cultivated. In children, as well as in men, the strength of that habit, or perhaps of that power of the mind which associates ideas together, varies considerably. It is probable, that this difference may depend sometimes upon organization. A child who is born with any defect in his eyes, cannot possibly have the same pleasure in objects of sight, which those enjoy who have strong eyes: ideas associated with these external objects, are, therefore, not associated with pleasure, and, consequently, they are not recollected with any sensations of pleasure. An ingenious writer[51] supposes, that all the difference of capacity amongst men ultimately depends on their original power of feeling pleasure or pain, and their consequent different habits of attention.
When there is any defect in a child's organization, we must have recourse to physics, and not to metaphysics; but even among children, who are apparently in the full possession of all their senses, we see very different degrees of vivacity: those who have most vivacity, seldom take delight in repeating their ideas; they are more pleased with novelty than prone to habit. Those children who are deficient in vivacity, are much disposed to the easy indolent pleasure of repetition; it costs them less exertion to say or do the same thing over again, than to attempt any thing new; they are uniformly good subjects to habit, because novelty has no charms to seduce their attention.
The education of the memory in these two classes of children, ought not to be the same. Those who are disposed to repetition, should not be indulged in it, because it will increase their indolence; they should be excited by praise, by example, by sympathy, and by all the strongest motives that we can employ. Their interest in every thing around them must by all means be increased: when they show eagerness about any thing, no matter what it is, we may then exercise their memory upon that subject with some hopes of success. It is of importance that they should succeed in their first trials, otherwise they will be discouraged from repeating their attempts, and they will distrust their own memory in future. The fear of not remembering, will occupy, and agitate, and weaken their minds; they should, therefore, be animated by hope. If they fail, at all events let them not be reproached; the mortification they naturally feel, is sufficient: nor should they be left to dwell upon their disappointment; they should have a fresh and easier trial given to them, that they may recover their own self-complacency as expeditiously as possible. It may be said, that there are children of such a sluggish temperament, that they feel no pleasure in success, and no mortification in perceiving their own mental deficiencies. There are few children of this description; scarcely any, perhaps, whose defects have not been increased by education. Exertion has been made so painful to them, that at length they have sunk into apathy, or submitted in despair to the eternal punishment of shame.
The mistaken notion, that the memory must be exercised only in books, has been often fatal to the pupils of literary people. We remember best those things which interest us most; which are useful to us in conversation; in our daily business or amusement. So do children. On these things we should exercise their memory. Tell a boy who has lost his top, to remember at such a particular time to put you in mind of it, and if he does, that you will give him another, he will probably remember your requests after this, better than you will yourself. Affectionate children will easily extend their recollective memories in the service of their friends and companions. "Put me in mind to give your friend what he asked for, and I will give it to him if you remember it at the right time." It will be best to manage these affairs so that convenience, and not caprice, shall appear to be your motive for the requests. The time and place should be precisely fixed, and something should be chosen which is likely to recall your request at the appointed time. If you say, put me in mind of such a thing the moment the cloth is taken away after dinner; or as soon as candles are brought into the room; or when I go by such a shop in our walk this evening; here are things mentioned which will much assist the young remembrancer: the moment the cloth is taken away, or the candles come, he will recollect, from association, that something is to be done, that he has something to do; and presently he will make out what that something is.