53+ THE POPULAR SCIENCE MONTHLY. 



to be a careful student of physiology and the laws of health. A 

 thorough knowledge of the scientific principles of healthy exer- 

 cise 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 re- 

 solved 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, al- 

 though 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 physi- 

 ology 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 intel- 

 lectual and moral natures are largely to be built. He is work- 

 ing 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 inter- 

 esting 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- 



