As for experimenting with children, only the psychologist should undertake it. The connections between the body and the mind are so close in infancy, the mere animal can do so much to ape reason, and the child is so helpless under the leading of instinct, impulse, and external necessity, that the task is excessively difficult--to say nothing of the extreme delicacy and tenderness of the budding tendrils of the mind. But others do experiment! Every time we send a child out of the home to the school, we subject him to experiment of the most serious and alarming kind. He goes into the hands of a teacher who is often not only not wise unto the child's salvation, but who is, perchance, a machine for administering a single experiment to an infinite variety of children. It is perfectly certain that a great many of our children are irretrievably damaged or hindered in their mental and moral development in the school; but we can not be at all sure that they would fare any better if they were taught at home! The children are experimented with so much and so unwisely, in any case, that possibly a little intentional experiment, guided by real insight and psychological information, would do them good. _Methods of experimenting with Children._--In endeavouring to bring such questions as the degree of memory, recognition, association, etc., present in an infant, to a practical test, considerable embarrassment has always been experienced in understanding the child's vocal and other responses. Of course, the only way a child's mind can be studied is through its expressions, facial, lingual, vocal, muscular; and the first question--i.e., What did the infant do? must be followed by a second--i.e., What did his doing that mean? The second question is, as I have said, the harder question, and the one which requires more knowledge and insight. It is evident, on the surface, that the further away we get in the child's life from simple inherited or reflex responses, the more complicated do the processes become, and the greater becomes the difficulty of analyzing them, and arriving at a true picture of the real mental condition which lies back of them. To illustrate this confusion, I may cite one of the few problems which psychologists have attempted to solve by experiments on children: the determination of the order of rise of the child's perceptions of the different colours. The first series of experiments consisted in showing the child various colours and requiring him to name them, the results being expressed in percentages of correct answers to the whole number. Now this experiment involves no less than four different questions, and the results give absolutely no clew to their separation. It involves: