umstances may be talked of in our hearing, of which we Jo not retain the slightest recollection; and this is often in such a degree as implies, not a want of memory only, but an actual want of the perception of the objects. We cannot doubt, however, that there was the sensation of them; that is, the usual impression made upon the eye in the one case, and the ear in the other. What is wanting, is a certain effort of the mind itself, without which sensation is not necessarily followed by perception;-this is what we call Attention. It is a state or act of the mind which is exercised by different individuals in very different degrees. It is much influenced by habit; and though it may not often be wanting in such a degree as to prevent the perception of objects, it is often deficient in a manner which prevents the recollection of them, and consequently has an extensive influence upon the intellectual character.

The effect of attention is illustrated by various mental phenomena of daily occurrence. If we are placed in such a situation that the eye commands an extensive landscape, presenting a great variety of objects, or the wall of an apartment covered with pictures, we have the power of fixing the mind upon one object in such a manner that all the rest become to us nearly as if they did not exist. Yet we know that they are actually seen, as far as the mere sense of vision is concerned; that is, images of all of them are formed upon the retina; but they are not objects of attention, or of that peculiar voluntary effort of mind which is necessary for the full perception of them. In the same manner, a practised musician can, in the midst of a musical performance, direct his attention to one part, such as the bass,-can continue this for such a time as he pleases, and then again enjoy the general harmony of the whole. On the same principle, the mind may be so intensely fixed upon something within itself, as an object of conception or memory, or a process of reasoning, as to have no full perception of present external impressions. We shall afterward have occasion to refer to a state of mind in which this exists in such a degree, that objects of conception or memory are believed to have a real and present existence; and in which this erro

Name of this? Effect of attention illustrated. In the sense of sight. Of hearing.

neous impression is not corrected by impressions from external things-this occurs in insanity.

Attention is very much influenced by habit; and connected with this subject there are some facts of great interest. There is a remarkable law of the system, by which actions at first requiring much attention are after frequent repetition performed with a much less degree of it, or without the mind being conscious of any effort. This is exemplified in various processes of daily occurrence, as reading and writing, but most remarkably in music. Musical performance at first requires the closest attention, but the effort becomes constantly less, until it is often not perceived at all; and a lady may be seen running over a piece of music on a piano, and at the same time talking on another subject. A young lady, mentioned by Dr. Darwin, executed a long and very difficult piece of music with the utmost precision, under the eye of her master; but seemed agitated during the execution of it, and when she had concluded, burst into tears. It turned out that her attention had, during the whole time, been intensely occupied with the agonies of a favorite canary-bird, which at last dropped dead in its cage. We see the same principle exemplified in the rapidity with which an expert arithmetician can run up a long column of figures, without being conscious of the individual combinations. It is illustrated in another manner by the feats of jugglers, the deception produced by which depends upon their performing a certain number of motions with such rapidity that the attention of the spectators does not follow all the combinations.

In teaching such arts as music or arithmetic, this principle is also illustrated; for the most expert arithmetician or musical performer is not necessarily, and perhaps not generally, the best teacher of the art; but he who, with a competent knowledge of it, directs his attention to the individual minute combinations through which it is necessary for the learner to advance.

In processes more purely intellectual, we find the influence of habit brought under our view in a similar manner,

Influence of habits of attention. Illustrations. Anecdote of the young lady. Other illustrations. Illustration of this principle from the art of teaching. Influence of habit in facilitating intellectual processes.

particularly in following the steps of a process of reasoning. A person little accustomed to such a process advances step by step, with minute attention to each as he proceeds; while another perceives at once the result, with little consciousness of the steps by which he arrived at it. For this reason, also, it frequently happens that in certain departments of science the profound philosopher makes a bad teacher. He proceeds too rapidly for his audience, and without sufficient attention to the intermediate steps by which it is necessary for them to advance; and they may derive much more instruction from an inferior man, whose mental process on the subject approaches more nearly to that which, in the first instance, must be theirs. We remark the same difference in public speaking and in writing; and we talk of a speaker or a writer who is easily followed, and another who is followed with difficulty. The former retards the series of his thoughts, so as to bring distinctly before his hearers or his readers every step in the mental process. The latter advances without sufficient attention to this, and consequently can be followed by those only who are sufficiently acquainted with the subject to fill up the intermediate steps, or not to require them.

There is a class of intellectual habits directly the reverse of those now referred to; namely, habits of inattention, by which the mind, long unaccustomed to have the attention steadily directed to any important object, becomes frivolous and absent, or lost amid its own waking dreams. A mind in this condition becomes incapable of following a train of reasoning, and even of observing facts with accuracy and tracing their relations. Hence nothing is more opposed to the cultivation of intellectual character; and when such a person attempts to reason, or to follow out a course of investigation, he falls into slight and partial views, unsound. deductions, and frivolous arguments. This state of mind, therefore, ought to be carefully guarded against in the young; as, when it is once established, it can be removed only by a long and laborious effort, and after a certain period of life is probably irremediable.

In rude and savage life remarkable examples occur of

Bad teaching. Public speaking. Habits of inattention. Consequences? Habits of attention in savage life.

the effect of habits of minute attention to those circumstances to which the mind is intensely directed by their relation to the safety or advantage of the observer. The American hunter finds his way in the trackless forests by attention to minute appearances in the trees, which indicate to him the points of the compass. He traces the progress of his enemies or his friends by the marks of their footsteps; and judges of their numbers, their haltings, their employments, by circumstances which would entirely escape the observation of persons unaccustomed to a mode of life requiring such exercises of attention. Numerous examples of this kind are mentioned by travellers, particularly among the aboriginal natives of America.

OF FALSE PERCEPTIONS.

BEFORE leaving this subject, it is necessary to refer to some remarkable facts respecting perceptions taking place, without the presence of any external body corresponding with them. These are called false perceptions, and they are usually referred to two classes; namely, those arising in the organs of sense, in which the mind does not participate; and those which are connected with hallucination of mind, or a belief of the real existence of the object. former only belong to this part of the subject. The latter will be referred to in another part of our inquiry, as they do not consist of false impressions on the senses, but depend upon the mind mistaking its own conceptions for real and present existences.

The

Of false perceptions, properly so called, the most familiar are the musca volitantes floating before the eyes, and sounds in the ears resembling the ringing of bells, or the noise of a waterfall. Changes are also met with in the organs of sense giving rise to remarkable varieties of perception. Dr. Falconer mentions a gentleman who had such a morbid state of sensation that cold bodies felt to him as if they were intensely hot. A gentleman mentioned by Dr. Conolly, when recovering from measles, saw objects dimi

Examples? False perceptions-what? How classified? Common examples.

nished to the smallest imiginable size; and a patient mentioned by Baron Darry, on recovering from amaurosis, saw men as giants, and all objects magnified in a most remarkable manner: it is not mentioned how long these peculiarities continued. This last peculiarity of perception occurred also to a particular friend of mine in recovering from typhus fever. His own body appeared to him to be about ten feet high. His bed seemed to be seven or eight feet from the floor, so that he felt the greatest dread in attempting to get out of it; and the opening of the chimney of his apartment appeared as large as the arch of a bridge. A singular peculiarity of this case however was, that the sons about him with whom he was familiar did not appear above their natural size. But the most interesting phenomena connected with affections of this kind are furnished by the various modifications of spectral illusions. These are referable to three classes.

per

I. Impressions of visible objects remaining for some time after the eye is shut, or has been withdrawn from them; generally accompanied by some remarkable change in the color of the objects. Various interesting experiments of this kind are related by Dr. Darwin; one of the most striking is the following:-"I covered a paper about four inches square with yellow, and with a pen filled with a blue color wrote upon the middle of it the word BANKS în capitals; and sitting with my back to the sun, fixed my eyes for a minute exactly on the centre of the letter N in the word. After shutting my eyes, and shading them somewhat with my hand, the word was distinctly seen in the spectrum, in yellow colors on a blue ground; and then on opening my eyes on a yellowish wall at twenty feet distance, the magnified name of BANKS appeared on the wall written in golden characters."

With a very little ingenuity, this kind of spectral illusions can be easily produced in great variety. Take a common red wafer, and lay it upon a sheet of white paper. Bring the eye down to within six or eight inches of it, and gaze very steadily and intently upon it for the space of twenty or thirty seconds. On moving the eyes away, a beau

False perception of magnitude. Examples of this. Spectral illusions; how many classes? First class? Darwin's experiments? Easy mode of producing these illusions.