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1891 mean?) When, therefore, an image of a past experience arises in our minds, unattended by any of its former companions, we can only feel that we re-know it, without being able to tell where or when.

How we know that Present Images are Copies of Past Experiences. This explanation of the fact would seem to make the explanation of our ordinary experiences in memory very simple. Usually when we see a thing a second time that we remember to have seen before, we remember when and where we saw it. The reason is, as we now see, that the image of the past fact is attended by some of the ideas that were in the mind at the same time, so that its place and time are fixed. But how do we know that images of which we are conscious in the present are copies of experiences that we had an hour ago, or rather what makes us believe it? You sit down and begin to indulge in the pleasure of retrospection. You think of what happened an hour ago, yesterday, last year, ten years ago when you were a child, first finding yourself in this strange world. But your base of operations is always the present. How is it that ideas now in the mind are retrojected, some of them an hour back, others a day, others a year, others a decade, others for a period not to be mentioned in such a public place? Precisely as in perception, we refer some of the sensations of color to objects ten feet away, others to objects a mile- ten miles away, while all of them are in our own minds, so in memory we retroject ideas, all of which are experiences of the present, some of them an hour, others a day, others a week, others a score of years into our past lives. As Mr. Ward puts it, "We may, if we represent succession as a line, represent

simultaneity as a second line at right angles to the first." As our experiences actually occur to us, they are in succession, the memory images of them at any one time are in the mind simultaneously. How are we able to retroject present memory images into that place in the past occupied by the experiences of which they are the copies?

Temporal Signs. It is the case of the Irishman's brogue over again. As we know the nationality of an Irishman by the way he speaks; as we refer our sensations to a certain place by their local signs; so we locate images of past experiences at a certain point in our past lives by their temporal signs. As the local signs are certain characteristics that all sensations, however different, which arise from the stimulation of the same part of the body have in common, so the temporal signs are certain common characteristics possessed by all ideas that we refer to some general point of time, however different those ideas may be. In other words, all the events of Christmas Day, 1888, that I am able to recall and localize at that point in the past are represented in my mind by ideas or images that have certain common characteristics. These common characteristics this brogue that enables me to refer my recollections to their proper time in the past temporal signs.

are called

QUESTIONS ON THE TEXT.

1. Define retention, reproduction, recognition, and localization, and show that they are essential to a complete act of memory.

2. Summarize the results reached in the chapter on the association of ideas.

3.

How is it that we sometimes know that we have seen a thing without being able to tell where or when?

4. What was the illustration of the Irishman's brogue used to show in one of the chapters on perception?

5. What is the difference between local and temporal signs?

6. How is it that the mind is able to regard its local signs as signs of place?

7. What is the difference between a percept and an image?

8. Show that we are able to locate a thing either in time or place only by its relation to other things.

SUGGESTIVE QUESTIONS.

1. Do you know any facts indicating that retention is made possible through a modification of the brain that results from each of the experiences of the mind?

2. If that is the explanation of retention, how would you explain reproduction?

3. On the supposition that the mind has temporal signs, how would you explain its power to interpret them as signs of time?

4. At about what age do children begin to understand the meaning of yesterday, last week, etc.?

5. Why is it that this knowledge comes so late?

6. Are you sure that such a thing as absolute forgetfulness ever takes piace?

LESSON XXVI.

THE CULTIVATION OF THE MEMORY.

Rules for Remembering. — Bearing in mind our conclusion that the basis of memory is in part physical, it is but a step to the further conclusion that whatever is learned in a state of excellent bodily health, other things being equal, is most likely to be remembered. Facts of every-day experience confirm this view. We all know how likely we are to forget things that we learn when we are suffering from a headache, indigestion, or the like.

Health and Memory.- Says a popular writer, Mr. Halleck: "The first rule for securing a better memory is to pay attention to the laws of hygiene, to endeavor by all means to keep the health at high-water mark."

Attention and Memory. Another rule, equally confirmed by daily observation, is: Attend carefully and closely to the facts you wish to remember. We have seen in a previous chapter how much memory depends on attention, and we know how much it depends on interest. interest in a subject increases the power to remember it chiefly through the influence of interest on attention. Many of us find it hard to remember faces. This difficulty

But

DRAWING AND MEMORY OF FORM.

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would be lessened if we carefully noted the faces of people we wish to remember.

Drawing and Memory of Form. Every teacher knows how the drawing of objects tends to fix their form in the mind. The reason is that in drawing objects we must attend to them. Sir Francis Galton says that M. Boisbaudran trained the visual memory of his pupils with extraordinary success. His method was to have his pupils study "the models thoroughly before they tried to draw them from memory. One favorite expedient was to associate the sight memory with the muscular memory by making his pupils follow at a distance the outlines of the figures with a pencil held in their hands. After three or four months' practice, their visual memory became greatly strengthened. They had no difficulty in summoning images at will, in holding them steady, and in drawing them."

Understanding and Memory. A third rule for facilitating the acquisition of memory is: Get a clear comprehension of the thing you wish to remember. The famous experiments of Elbringhaus illustrate this in a striking way. He found that he could memorize a stanza of poetry in about one tenth of the time required to memorize the same amount of nonsense syllables. I asked a capable student of Johns Hopkins University some years ago to give me an account of a lecture he had just listened to. "I can not do it," was his reply. "It was not logical."

Association and Memory. The last example belongs, perhaps, with more propriety under the fourth and most important rule: Multiply associations, entangle the fact you