methods (i.e., those which exhaust the vital powers and create bad habits of mental sequence) by the fact that the former are conformed to the central or fundamental law of Thought-sequence.
The physiology teacher lays on his table two specimens of the same bone; one from which all the gelatine has been boiled, and the other from which the phosphates have been discharged by acid, leaving only a gelatine shape. The class are instructed to examine each separately, and then to form a mental picture of a bone in which these two structures mutually interpenetrate each other. The teacher probably supposes himself to be merely illustrating the structure of bone; but in reality he is illustrating the fundamental law of sound mental action. Would that all teaching was done on the same model! We should then hear very little about "breaking down from over- work in schools!"
The bone-lesson above referred to gives the standard model on a very minute scale; education should copy that model on various scales of size. The rhythmic beats of alternate specialization and synthesis may vary from the five minutes or so occupied by the bone-lesson, to a period of a whole year; they should be of various degrees of complexity; from learning to see as one, two aspects of the same bit of bone, to learning to see what light the year's lessons on History, Language, Mathematics, and Physical Science throw on each other's meaning. The most important rhythm would appear to be one whose pulsation occupies about seven days.
Gratry has pointed out how the habit of periodic synthesis of different branches of study strengthens the mind and enables it to do a marvellous quantity of work