constitute memory, neither does that increased functional activity which results from stimulation when not excessive.

As an impression must reach a certain sum of intensity before it is brought before the consciousness, the greater number of impressions never become revived, because this intensity is not attained. They remain in a latent condition, waiting for an appropriate stimulus for their revival to take place. How often the most trivial incidents are brought back, by some strong resemblance or association-events and details so far forgotten, that if narrated by others, they would not have been recognised as having occurred.

There are very few persons, excepting perhaps the most feeble-minded individuals, who are not able to recognise an anecdote when told with all its details by another a second time, at a comparatively short period after the first recital, though they might not have been able to repeat it correctly themselves. If the original modification of the protoplasm caused by the anecdote had disappeared, then no stimulus, however strong, would be able to bring it back to the mind. It is very rare for a person not to remember an occurrence if he be placed in exactly the same circumstances as when he received the original impression.

The following are instances of the revival of old impressions. Numerous cases might be given, as examples of this class are very common :

1. Several years ago, the Rev. S. Hansard, now rector of Bethnal Green, was doing clerical duty for a time at Hurstmonceaux, in Sussex; and while there he one day went over with a party of friends to Pevensey Castle, which he did not remember to have ever pre

viously visited. As he approached the gateway, he became conscious of a very vivid impression of having seen it before; and he seemed to himself to see not only the gateway itself, but donkeys beneath the arch, and people on top of it. His conviction that he must have visited the Castle on some former occasion--although he had not the slightest remembrance of such a visit, nor any knowledge of having been in the neighbourhood previously to his residence at Hurstmonceauxmade him inquire from his mother if she could throw any light on the matter. She at once informed him that, being in that part of the country when he was about eighteen months old, she had gone over with a large party, and had taken him in the pannier of a donkey; that the elders of the party having brought lunch with them, had eaten it on the roof of the gateway, where they would have been seen from below; whilst he had been left on the ground with the attendants and donkeys. This case is remarkable for the vividness of the sensorial impression (it may be worth while to notice that Mr. Hansard has a decidedly artistic temperament) and for the reproduction of details which were not likely to have been brought up in conversation, even if he had happened to hear the visit itself mentioned as an event of his childhood, and of such mention he has no remembrance whatever.'CARPENTER: Mental Physiology.'

2. 'A lady in the last stage of chronic disease was carried from London to a house in the country; there her infant daughter was taken to visit her, and after a short interview carried back to town. The lady died a few days after, and the daughter grew up without any recollection of her mother till she was of mature age.

At this time she happened to be taken into the room where her mother died, without knowing it to be so. She started on entering it, and when a friend who was with her asked the cause of her agitation, she replied, “I have a distinct impression of having been in this room before, and that a lady who lay in that corner, and seemed very ill, leaned over me and wept." ABERCROMBIE: Intellectual Powers.'

3. The following is related by Coleridge, and shows how impressions, not understood in the least by the patient, were still registered and brought forth under the influence of appropriate stimuli:

In a Roman Catholic town in Germany, a young woman, who could neither read nor write, was seized with a fever, and was said by the priests to be possessed of a devil, because she was heard talking Latin, Greek, and Hebrew. Whole sheets of her ravings were written out, and found to consist of sentences intelligible in themselves, but having slight connection with each other. Of her Hebrew sayings only a few could be traced to the Bible, and most seemed to be in the Rabbinical dialect. All trick was out of the question-the woman was a simple creature; there was no doubt as to the fever. It was long before any explanation, save that of demoniacal possession, could be obtained. At last, the mystery was unveiled by a physician, who determined to trace back the girl's history, and who, after much trouble, discovered that at the age of nine she had been charitably taken by an old Protestant pastor. On further inquiry, it appeared to have been the old man's custom for years to walk up and down a passage of the house into which the kitchen opened, and to read to himself

with a loud voice out of his books. The books were ransacked, and among them were found several of the Greek and Latin Fathers, together with a collection of Rabbinical writings. In these works so many of the passages taken down at the young woman's bedside were identified, that there could be no reasonable doubt as to their source.'-' Biographia Literaria,' 1847.

The centre for sensory memory is so arranged that every impression, received through a lifetime, is registered in a definite position and order of sequence, from the first moment of a child's life to the day of his death, and all sensations, perceptions, and ideas, received at the same time, either form component parts of one impression or closely associated impressions.

Of course, the above only applies to the brain when in a normal state, as departure from it is evidence of disease, amongst which must be classed those cases of senile failure in registering impressions.

A very rough illustration of the above may be given as follows: Supposing the centre for sensory memory, when the child is born, be represented by one side of a room covered with blank paper, then as time goes on, and he grows older, the paper becomes gradually covered with small pictures, words, &c., exactly as he has received the impressions; and so the process goes on, an addition being made every time an impression is received.

This illustration is only intended to exemplify the above fact, and not meant to imply more than that there is a position and order in the registration of impressions, not that the centre for sensory memory is filled up like the paper from left to right, as there is no proof that such is the case. It is probable that

what occurs is similar to the processes which bring about other periodical physiological conditions which occur with regularity and order of sequence, and at certain definite times. Thus, it is easy to suppose that the portion of the centre for the sensory memory corresponding to the first part of the blank wall is only developed in babyhood, and that the remainder is in a more or less embryonic state, and becomes gradually developed, to be ready when required.

Such a view as the above is in perfect conformity with our own sensations; we do not confuse an intense impression received in the past with one acquired more recently. We have a definite idea of the past, and though we may not be able to remember the details, we readily recognise them when related by others, and rarely confuse impressions. It is also a fact of common note, that the recollection of an event, which took place in days gone by, is quite sufficient to recall a number of circumstances which happened about the same time, and which bear no relation whatever to the first remembered fact, except that they happened

about the same time.

We are able to perceive impressions of the past without any relation to the intermediate links. It is within the realm of nearly everyone's experience, to try to recollect some conversation, name, or circumstance, and find that he is unable to remember anything about it, and often to deny that such had ever happened; but in the course of the conversation some word suffices to revive the past impression, and the whole is brought vividly before the mind.

This shows the strong contiguous association of impressions received about the same time, which can