for the performance of muscular movements that have to be learned.

There are, therefore, two chief divisions of memory, each containing numerous subdivisions.

1. The general memory of all sensory impressions, both external and internal-GENERAL SENSORY MEMORY.

This is subdivided into the memories consisting of groups of specially intensified constituents of the general sensory memory, formed by the action of particular faculties of the mind-THE SPECIAL SENSORY MEMORIES.

2. The memory required for the continued performance of coördinated muscular movements-GENERAL MOTOR MEMORY.

This is subdivided into the memories consisting of specially intensified portions of the motor memory required for the performance of definite actions-THE SPECIAL MOTOR MEMORIES.

Sensory memory has only to deal with sensory impressions, motor memory with those motor impulses from the brain which are required to bring about a voluntary movement. It is from ideas, derived from sensory memory impressions, that movements are attempted; but it is by means of the motor memory that these movements are performed with increasing rapidity and with less attention. The following example will show how special sensory memories differ in individuals, and the relation they bear to one another.

Let us suppose that there were several persons on the top of the Monument, looking at London. A coloured photograph would represent the view, fairly well. The general impression would be the same; thus, most

would agree that the photograph was an accurate representation of what they saw. But if each of these persons, previously to seeing the photograph, had given a description of the view, the following would have been the probable result:

The man of a low intellectual type, whose principal object in going up the Monument was that of being able to say that he had done so, would probably recollect absolutely nothing. When he was on the Monument he observed nothing in particular.

The man of observation, who can remember what he sees, would examine the details of the scene and notice the various buildings, a process which is quite distinct from mere seeing, insomuch as it consists in bringing the mind to bear upon an impression in the centre for the sensory memory. Then if he were asked to describe what he had seen, he would think of how the buildings looked, and what he had recognised, and so remember the whole.,

Another man, who had a good memory for the relative positions of objects, would notice the relation which the various streets and buildings had to one another. For instance, that the river was on his left hand, Cannon Street Terminus on the right, St. Margaret's Church behind, and so on. When asked, some time afterwards, 'Did you see St. Dunstan's Church?' he would try to think of the relation the churches had to the other buildings, and would answer, Yes; it lay between the Monument and the Tower'

An architect would criticise the construction of the town, especially anything connected with his business, such as faulty architecture, erratic bridges, and so on. He would remember them by the errors or improve

ments which suggested themselves to his mind at the time of observing them.

A historian would recall to his mind facts and incidents connected with the various objects that he saw. Thus, on being asked if he had seen William IV.'s statue, he would reply, 'Oh yes; it occupies the site of the old Boar's Head, mentioned by Shakespeare as the place where Falstaff used to drink.'

A geologist, a sailor, a schoolmaster, and an artist, would each remember different portions of the view: they would each notice the objects that they were specially acquainted with, and overlook those with which they were not familiar. It may be said, that the particular profession or business, in the above-mentioned instances, is sufficient to account for the different descriptions given by each, but it must be remembered. that, in the majority of cases, it is the possession of certain predominating faculties, that leads an individual to select a certain profession or business, in preference to others; a cowardly man would never voluntarily become a soldier, or a man who found a difficulty in mastering the multiplication table, an accountant. man who was colour-blind might make a very good engraver or sculptor, but would be a failure as an artist.

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The foregoing examples are sufficient to show how memory differs in individuals. If any half-dozen persons were to read the same book, or look at the same pictures together, and then each write a detailed account of the same, the above-mentioned differences would be found.

The above instances could be multiplied indefinitely, each faculty, intellectual, moral, or emotional, when pre

dominating, influencing the possessor to notice those things which, as it were, 'supply those faculties.' This clearly distinguishes between general and special memory, the latter being the special groups of impressions obtained by the influence of particular faculties of the mind. How the faculties build up these special memories will be discussed at length in a future chapter.

Then, supposing a coloured photograph to represent the general memory-impression, all the varieties and shades of colour will represent one special memory group of impressions, the forms of the objects another group, and so on.

It now only remains to distinguish between general and special motor memory. The memory of all movements, no matter for what purpose produced, belongs to general motor memory, whilst the specially intensified memory required for the performance of certain definite actions is special motor memory. For example, the motor memory required for the performance on a musical instrument is one variety of special motor memory; the motor memory required to skate, ride, dance, speak, or write, other varieties, being special portions of the general motor memory required for a definite purpose, and influenced by several faculties, which vary according to the variety produced.

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CHAPTER III

SENSORY MEMORY

SENSORY memory depends absolutely upon the sensory impressions received, as elaborated by the sensory nerves; we have cognizance of the world (probably only in part as it really exists) as our senses inform us of its existence. The senses allow of a certain amount of substitution, one for the other, but each has its special function, which cannot be replaced by any of the others. Thus the ear takes no account of light, neither does the eye have cognizance of sound; so we can never judge of bodies as material substances otherwise than by the senses we possess; in fact, it seems difficult to conceive how bodies could possess properties which we are not able to recognise by the senses we have; but the study of science shows that such is the case. An illustration will better explain this. It is impossible to explain to a man who has been born blind what sight is; he is unable to appreciate what such a sense can be, and so does not feel the want of it in the same way as a man who has once been possessed of sight. It is the same with a person who has been born without the sense of smell; he is quite unable to conceive what such a sense can be, and does not feel its want. A man who has been born deaf and dumb can have no ideas of sound. very common instance is that of a myope who has

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