to be a careful student of physiology and the laws of health. A thorough knowledge of the scientific principles of healthy exercise and study enhances a teacher's usefulness. If the adage "knowledge is power" be true anywhere, surely it is true here. Possessed of a knowledge of the anatomy and physiology of the nervous system—a task which any intelligent teacher could master in a few months—he can deal with the whole question of the education of his class under a new and clearer light. Much that was a mystery to him regarding the acquisition of knowledge will become plain. The complex memory of a flower will be resolved into the memories of its several qualities, that were carried to the brain by conducting nerves. The association of ideas and the laws governing the same will be as simple as a lesson in elementary botany. The smelling of a rose reviving the memory of its color will cease to be an enigma. It will then become clear how a person may lose the power of speech and still be able to write and read; or how he may be able to read and write, although unable to hear spoken words; or, again, how he may have lost the power of hearing spoken words, and yet be able to speak, read, and write.
If any one should say that such a knowledge of the physiology of the nervous system in its relation to the acquisition of learning is of no use to the teacher, then I would reply that it is not necessary for the engineer to understand the engine he is running, the mariner the course he is sailing over, nor the farmer the nature of the soil he is tilling. The teacher has a number of young human beings placed under his charge. He is guiding them into the wide ocean of truth and thought. He is laying the foundations on which the future structure of their intellectual and moral natures are largely to be built. He is working with one of the grandest mechanisms known to man—the brain of the child! He ought therefore to know not only what he has to teach, but the subject that has to be taught and the best methods of teaching it. It can not be too strongly urged that if there be any derangement or want of harmony in these factors much of the good that might follow is lost. In order that the relationships between the nervous system and education be properly maintained the teacher must be thoroughly familiar with all three great divisions of his work—the things to be taught, the methods of teaching them, and the brain and sense organs that are to be developed. When the teacher has made himself master of the channels through which the child must acquire its knowledge it becomes an easier and a far more interesting work for him to select topics within the range of the child's understanding and experience. If he is a wise teacher he can build up the child's powers of observation for natural phe-
