At the other end of the scale is mere feebleness of mind. Such chil dren can be taught to read, and are capable of great improvement by kind ness and perseverance. Even in the higher class of idiots speech is usually defective, partly from malformation of the mouth ; partly from want of co-ordination of the lingual muscles ; but chiefly, no doubt, from the poverty Of their vocabulary, and the small stock of words to which they attach any definite meaning. In all the severer forms of idiocy no attempt at speech is ever made ; and, as Griesinger observes, the idiot who does not speak has no internal idea of speech, and is therefore "deficient in the most essential element in the mechanism of abstraction." Idiocy has been described as a fixed infantile condition, and the idiot has been compared, as regards intelligence, with a healthy child of so many months or years of age. An idiot, however, is not merely a backward With him volition is feeble or quite absent ; and he has little imagination or power of abstract thought. Therefore, although his actual degree of intellectual development may correspond with that of the younger child, there is a something still wanting, which if wanting in the child with whom he is compared would occasion very serious anxiety. Sometimes one faculty is developed in idiots to the exclusion of all others. In all treatises on this subject instances are given showing remarkable aptitude for music, drawing, and reckoning ; also for various forms of mechanical construction as carpentering, model-making, etc.
Diagnosis.—Icliocy must be distinguished from mere backwardness, and also from cases where the development of the mental faculties suffers through deficiency in the sense of hearing.
Mere backwardness, even when present in a marked degree, is far re moved from idiocy. The class of backward children presents many points of interest. The delay in development is usually physical as well as men tal. They are small but not usually deformed ; and there is no symptom of disease of brain or disorder of mind. They are simply backward chil dren in whom progress of every kind takes place very leisurely. Instead of learning early to walk, and picking up words and ideas with the quickness of a healthy child, they are slow to walk, slow to talk, slow to quit the habits and helplessness of the baby for the decency and independence of later childhood. Still, they do not remain stationary like the idiot ; they do learn, although slowly ; and with patience can be taught in time much that forms the education of a child of ordinary capacity. Backward chil dren, however, sometimes become idiotic. If they happen to be also epi leptic or addicted to self-abuse, they may gradually become duller and duller and fall into a state of complete idiocy.
In all cases of backwardness, especially of lateness of talking, with ap parent dulness of mind, the state of the hearing should be inquired into. A child who hears imperfectly is always slow in acquiring the power of ar ticulation ; and besides, as Dr. West has pointed out, his difficulty with this defect of keeping up intercourse with other children makes the patient dull, suspicious, and unchildlike.
Idiocy, when confirmed, is of interest chiefly to the specialist. The ordi nary practitioner is most concerned with the early symptoms of mental fee bleness, as this is seen in the infant. Nothing is commoner than for the family physician to be consulted because the baby " does not seem to take notice." In a healthy infant the senses come into play in the following order : Sight is the earliest to manifest itself. A fortnight after birth the infant's eyes should follow a light, as that of a lamp ; and at the end of a month or six weeks he is often able to recognise his nurse and will smile when she approaches. During the first few weeks babies often squint, especially
when looking at a near object. Later they become more expert in focus ing their eyes to suit various distances.
The child seldom gives evidence of hearing sounds before the third month, although Darwin states that his infants started at sudden noises when under a fortnight old. Babies do not recognise voices until after the fourth month, and it is the eighth or ninth mouth before they begin to recognise objects by name.
With regard to movements : a child of two months of age will raise his head from the pillow ; and after the third month will begin to use his hands and to toss up his head. At this time (the third mouth) he can support his head well. It is usually the ninth month before the child " feels his feet," i.e., presses his soles to the ground when held to the floor. He should walk some time between the tenth and the eighteenth month.
A healthy infant should keep his tongue within his mouth from the earliest age. His fontanelle should not close before the eighteenth month, nor be completely ossified before the end of the second year.
The faculty of speech is acquired much more quickly by some children than by others. Most babies will begin to say words after the end of the first year, and many can talk freely by the end of the second.
It is seldom before the end of the sixth month that any suspicion is felt that all is not right with the infant's mental development. Then it is usually the vacancy of his expression, the absence of any smile to greet his mother's approach, some peculiarity in his way of taking food, and the dead weight of the child as he lies with his head back in his nurse's arms that first excites the anxiety of the parents. In such cases we notice the weakness of the muscles of the back and neck, and their inability to sup port the head or keep the body erect for a moment, the nystagmus, the vacant look in the eyes, which never seem to fir upon an object, and can not be made to follow it when it is moved before them, the abnormal flow of saliva from the mouth, and the passiveness of the child's hand when a finger is placed in it—so different from what occurs with the healthy baby who at once squeezes anything which touches his fingers. On inquiry we find either that the child is always whining, or that he is strangely silent and pays no attention to sounds which please other infants of his age ; also, perhaps, that he takes the breast or bottle very slowly, and often makes a curious choking noise at the back of his nose. In such cases we gener ally find that the palate is narrow and highly arched (the V-shaped palate) ; that the head is small and of a curious shape—unsymmetrical, or very high and narrow in the crown ; that the fontanelle is excessively small or quite closed ; that the hands and feet tend to be cold ; that the muscles feel flabby, and on examination we can sometimes discover a congenital heart complaint, a club foot, or some other form of congenital deformity. Dr. Langdon Down has drawn especial attention to the appearance and posi tion of the ear. A helix or the lobule may be quite absent, and the piuna is often planted farther back in relation to the head and face than in the healthy child. Dr. Down also directs that the position of the eye, as to obliqueness, as well as degree of separation, should be noted, as there is often an approach to the ethnical variety described by this physician as the Mongolian type. Also, that the integument about the eyes should be examined for semilunar folds of skin at the inner canthus (epicanthic folds), which are more common in feeble-minded infants than in the healthy.