CHAPTER VI

THE SPECIAL MEMORIES

Functions of the Individual Faculties.

The functions of each particular faculty will now be discussed, but it is important to note that in the following descriptions many well-known names of faculties, as acquisitiveness, self-esteem, &c., are used for the sake of convenience, the terms fairly well expressing their functions; but beyond the definitions given in the following pages, no other function must be assumed to belong to them, as in many books, written and spoken language are included under the same faculty, which a very little experience is sufficient to show is practically, as well as theoretically, wrong. Again, the memory of any impression has been shown to be distinct from the perception, though intimately connected with it, and many other minor differences will be noticed under the separate faculties. The definitions given here are in accordance with my own experience of the functions of the faculties, and I hope will be found sufficiently accurate for all practical purposes. When any faculty is subsequently referred to, its functions will be understood to mean those given here, and this will be of importance to anyone wishing to ascertain the constitution of his own mind, so as to be able to use his

faculties in the most advantageous way, in the cultivation of his memory.

In the majority of instances, realers will find that they have all the faculties in an average degree, variations rarely being very great, either above or below the average. Occasionally, exceptions are to be found in which some faculty is either particularly large, or particularly small, and to these the exceptional examples apply. A student should try to form as accurate an idea as he can as to the size of the faculties he possesses. In order to facilitate the attainment of this object I will first give the functions of each faculty, and then the special memory which is developed by its possession, giving for examples persons who have been gifted, by having a large development of the faculty in question. When a large faculty is spoken of, in the following pages, it is not meant that this should be taken literally, but only in relation to its function.

1. Faculty of Colour.

The designation of this faculty explains its function, namely, that of conveying to the mind, from the general memory, impressions of colour, that is, contiguous combinations of psycho-physical colour units. When largely developed, the individual takes the greatest interest in colours, and can easily remember minute differences. between them. It is the faculty of the painter, as distinguished from the draughtsman. The spectrum, as usually observed, forms an admirable illustration of a psycho-physical series, six colours being clearly distinguished, each colour blending by imperceptible gradations with the adjacent members of the series. The psycho-physical does not correspond to the physical

series, as there is no break in the latter, which consists of rays gradually increasing in refrangibility from the red to the violet. The average psycho-physical series has only six units, the mind perceiving all rays within a certain range of refrangibility as red, those beyond this range as orange, and so on. The physical light series is also of greater length than that represented by the spectrum, there being rays, both below the red, and above the violet. If the spectrum be looked at through a piece of cobalt glass, a bright crimson will be seen below the red, whilst the presence of rays above the violet is demonstrated by fluorescence and other phenomena.

Each of the colours of the spectrum is primary, and cannot be again split up; thus, if after white light has been dispersed by a prism, another prism be inserted in the track of the first, so that only one colour shall be refracted at a time, it will be found that the individual character of each will be preserved. Again, a pure blue when mixed with a pure yellow does not give green as a resultant. If a spectral blue be mixed with a spectral yellow, the resultant will be white. If red and yellow are mixed together, an orange is obtained which is indistinguishable from the orange of the spectrum. Now, the orange of the spectrum is produced by rays of light having wave-lengths quite different from those of the red or yellow, therefore, the perception of similarity must be mental. The cause of the phenomenon is this: the psycho-physical colour series consists of six units (six is the average number, there being more units if the faculty of colour be large, less if it be small), and, therefore, all colours are perceived by any particular individual as combinations of

these colour units. Colours may also be modified by a greater or lesser admixture of white light. The physical intensity of a colour depends upon the number of rays, of a similar character, which are received on the retina at the same time. When a mixture of red and yellow is brought before the mind as a sensory impression,

previous impressions of red and yellow are revived, and as it is perceived that it is neither one nor the other, but midway between the two, and the mind having no cognizance of any colour other than orange between red and yellow, it is called orange, and on future occasions, orange is revived and brought before the mind by a mixture of red and yellow. This will be made clearer

when the laws of remembrance have been discussed, and exactly corresponds to the results of the experiments with the pseudoscope on the human face, in which we have positive proof that the mind does not necessarily perceive the impression on the retina, as received. When two colours possessing very different wave-lengths, as red and blue, are mixed together, a new colour is formed, 'purple,' which differs from the prismatic colours in being more readily perceived as a mixture. All the phenomena of colour may be explained by psycho-physical perception, the rays. situated on the border lines between the psychophysical colour units being especially liable to be perceived differently, according as the contiguous colours

vary.

Figure 1 shows the physical light series, the length of the waves being indicated by the length of the lines. a and b indicate the two points of greatest difference, namely, those at the ends of the series: c indicates the third point of difference, d the fourth, e the fifth. It will be seen that whilst there are several fourth and fifth points of difference, there is only one each of the first, second, and third points. In a psycho-physical series there is only one of each, and they appear first on one side and then on the other. Figure 2 shows two absolute psycho-physical units, one in the red and one in the violet, aa' and bb': as all the rays included between aa' and bb' appear absolutely alike, any one ray, as that at c, might be substituted. Figure 3 shows the absolute psycho-physical units in the approximate psycho-physical unit green. Figure 4 shows the absolute psycho-physical units in the approximate units red and violet.