The following are samples of classifications used: Esquirol-According to the powers of speech. 1. Those individuals using short phrases. 2. Those using monosyllables. 3. Those making cries only. 1. Simpletons, those individuals using simple sentences. 3. Idiots, those using simple sounds. Hoffbauer-According to powers of judgment. Seguin-According to physiological conditions. 1. Profound idiocy, the central organs affected. Duncan and Millard-According to physical defects. Eight classes. 1. Complete idiocy, which is absolute idiocy either congenital or acquired. 2. Incomplete idiocy, that which is susceptible of amelioration either congenital or acquired. 3. Congenital or acquired imbecility. 4. Mental debility. Piper-According to the presence or absence of convulsions. 1. Absolute idiocy, complete absence of attention. 2. Simple idiocy, weak attention. 3. Imbecility, fickle attention. Ireland-Pathological. 1. Genetous. 2. Microcephalic. 4. Eclampsic. 5. Epileptic. 7. Traumatic. 8. Inflammatory. 10. Syphilitic. 11. Cretinism.1 Tuke 3. Hydrocephalic. 6. Paralytic. 9. Sclerotic. 12. Idiocy of Deprivation. 1. Those who exhibit nothing beyond the reflex movements known as excito-motor. 2. Those whose reflex acts are consensual or sensori-motor, including those of ideo-motor and emotional character. 1 As the cause for cretinism has been found to be a lack of certain chemical constituents in the blood, it is possible that idiocy in some of its other forms may be traced to a similar cause. Instead of classifying defectives according to mental traits, or physical symptoms or the kind of treatment needed, from a medical standpoint at least, the most helpful classification might be one based on the chemistry of the idiot.' 3. Those who manifest volition-whose ideas produce some intellectual operations and consequent will. §3. Criticisms of the Available Literature FROM the definitions and classifications quoted, it is evident that there is great diversity of opinion upon these two fundamental matters of psycho-asthenics. This is but a sample of the confusion and disagreement that is found with reference to almost every other fact mentioned in the literature on the subject. There is very little exact detailed description of the mental or physical make-up of defectives. We find scattered observations of single cases in medical records and the reports of physicians, which are concerned chiefly with causes for idiocy and the accompanying brain conditions, with vague generalizations about defectives as a whole and with few or no facts to support them. The only exact measurements which I have met are those of Jacobs, Galton, Johnson, Wylie and Kelly, which will be discussed later. There are several reasons for this condition of affairs. In the first place, writers differ materially as to the cause of idiocy, some maintaining that the condition is due to malformation of the brain, others that it is due to a diseased condition, and still others that it is due to retarded development, the condition being that of an individual reaching a lower stage of development than the normal person. This seems to be a matter of opinion, since the histology of the brain, in different conditions, is as yet very incompletely worked out Ireland says that "save in the cases of hydrocephalic and microcephalic idiots, the size of the head gives no estimate of the compara tive intelligence of the children." And again both Barr and Ireland agree that "mental capacity diminishes with the brain weight if we use large weights; but if we use smaller weights, two or three ounces for example, we soon find that we can not establish a constant relation between the size of the hemisphere and the amount of mental power shown." However, these opinions do not deal with the structure of the brain. As to the presence of disease, Wilwarth holds that of the brains examined only fifty per cent. were diseased. The only work which truly touches the points mentioned above is that of Ham marberg, published in 1893. This work has not been continued; a least no further work supplementing it has been given to the public His result rests upon the examination of the brains of nine idiots He holds that all idiots have fewer cells in the brain than other people, also that the cells are simpler. In some cases this lack of development may be limited to only one part of the cortex. He find three types of development: (1) Development of the brain become impaired in embryonic stage. No development of consciousness of conception is possible. (2) Development of the brain becomes im paired in a higher embryonic stage or in the first year of life. Con sciousness and conception are possible, but no higher development (3) Development of the brain is impaired during the first year of later; one section is most affected, but the whole brain reaches th development of a younger normal child. Consciousness and con ception are possible, but no higher station can be reached by th individual. In the fields of brain histology and physiological chemistry wil probably be found the answers to many of the debated points in thi subject, but until there has been more research along these lines w can not hope for agreement among writers in general. A second cause for conflicting opinions has been the fact tha idiocy in all its grades has been confused with insanity, and the man ner of treatment and the investigations of insanity have been made to serve also for feeble-mindedness. However, this fallacy has been avoided by some of our recent writers and such treatment is not found in the newer books on the subject. The third reason for the diversity of opinion may be found in the point of view taken by the investigator. The basis for classification chosen may be etiology, symptomatology, pathological anatomy or education, and with this difference in point of view-a difference which must tinge the whole investigation-it is no wonder that we find statements which are even contradictory. A fourth reason, and to my mind the most important one, is the lack of scientific experiments as to both the physical and the mental traits of the idiot. § 4. Summary of Previous Experimental Work EXPERIMENTAL evidence as to the position occupied by idiots in various mental and physical traits as compared with the position occupied by ordinary children in the same traits, is the only means of definitely answering questions in the psychology of idiocy. From such exact measurements as exist, namely, those of Jacobs, Galton, Johnson, Wylie and Kelly, we get the following facts. Jacobs, when using the digit test in order to ascertain the memory span of school children, thought that his results would mean more could the tests be given over a wider range of intellectual ability; Galton accordingly supplemented his work by giving approximately the same tests to 44 feeble-minded children. The conclusion drawn from this work is simply that none of the idiots attain the normal memory span— the average for the idiots being 4 digits. In the Psychological Review for July, 1903, R. S. Kelly reports a comparative study of psychophysical tests on normal and abnormal children. The tests were given to the children in the elementary school of the University of Chicago and to those in the Chicago Physiological School. "The tests may be divided roughly into three classes. There were the ordinary tests of the senses of hearing, sight, taste, smell, touch and temperature, together with sensitiveness to pain. There was a series of muscular tests involving numerous forms of muscular coordination with special reference to rapidity, accuracy and steadiness of movement and fatigue. And third, a number of tests were made with special reference to prevalent forms of imagery in peculiar types of children, certain emotional reactions, etc." Quoting the results which bear directly on the tests given: "(4) Approximate uniformity of results in psychical reactions is characteristic of healthy consciousness. Inability to secure this uniformity is at once a sign of a neurotic condition, which if ne lected may become permanent. (5) ... A child of arrested deve opment has a well-developed automobile consciousness. He h power of imagery with reference to this machine, visual, audito and motor, which measured in terms of race development alone wou indicate a degree of intelligence far advanced. ... (7) These tes with both classes of children agree in indicating that touch is a mo primitive sense than color. It develops first and maintains its pr cedence for some years. (How long is as yet undetermined.) ( (8 Bright colors are generally preferred by these abnormal childre (9) The grosser movements of the body develop before the finer on There is greater accuracy and rapidity of movement with the shou der than with the finger, and this rule is followed by children up the highest group (tenth) in the Elementary School. (10) The is a uniform increase of ability in motor coordination as the intel gence rises. (12) The lower the intelligence the more promine the element of fatigue appears. (15) It is quite possible for t simple motor test which discloses the degree of intelligence to be conducted as to give ethical data as well. (16) The abnormal chi is deficient in intensity and not in extent of psychic function." The main criticisms of these results are two in number. In t first place the author has not treated enough cases to make his resu reliable, especially in the case of the defective children. In some the tests the number of cases tested is not stated and in no instan is the result obtained for more than sixteen children. In the seco place the conclusions quoted are often vague and do not seem to gr directly out of the tests. Probably the most extensive measurements of the feeble-mind have been made by Dr. R. T. Wylie and reported in the Journal Psycho-Asthenics (Vol. IV., No. 3; Vol. V., No. 1; and Vol. VI No. 1), which I copy almost in full. His measurements of t height and weight of the feeble-minded children taken in their or nary school clothes are given in the table on the opposite page. "To study the condition of taste among the lowest grade feeble-minded children, the author made use of sugar, quinine s phate, tartaric acid and salt, applying them to the tongue a noticing if the subject gave any indication of a difference. Thir five boys and thirty-one girls were tested. Of these eight girls a fifteen boys, or 24 per cent. of all, gave no indication of a differen Eight boys and eight girls, or 17 per cent. of all, showed a differen for quinine; twenty-one girls and nineteen boys, or 41 per cent. all, showed a difference for tartaric acid; and fifteen girls and sev boys, or 23 per cent. of all, showed a difference for salt. Thus t |