5 1 4 THE POPULAR SCIENCE MONTHLY. 



that the consideration of all the known conditions that favor or 

 impede the plastic growth of the system should be searching and 

 minute. 



Although some philosophers have taught that all minds are nearly- 

 equal in regard to facility of acquirement, a schoolmaster that would 

 say so must be of the very rudest type. The inequality of different 

 minds in imbibing lessons, under the very same circumstances, is a 

 glaring fact; and is one of the obstacles encountered in teaching 

 numbers together, that is, classes. . It is a difficulty that needs a great 

 deal of practical tact or management, and is not met by any educa- 

 tional theory. 



The different kinds of acquirements vary in minor circumstances 

 which are important to be noticed after exhausting the general or 

 pervading conditions. The greatest contrast is betw T een what belongs 

 to intelligence, and what belongs to the feelings and the will. The 

 more strictly intellectual department comprises Mechanical Art, Lan- 

 guage, the Sensible World, the Sciences, Fine Art; and to each -of 

 these heads may attach specialties not hard to assign. 



General Circumstances favoring Hetentiveness. 1. The physical 

 condition. This has been already touched ivpon, both in the review 

 of physiology, and in the remarks on discrimination. It includes 

 general health, vigor and freshness at the moment, together with the 

 further indispensable proviso that the nutrition, instead of being 

 drafted off to strengthen the mere physical functions, is allowed to 

 run in good measure to the brain. 



In the view of mental efficiency, the muscular system, the digestive 

 system, and the various organic interests, are to be exercised up to 

 the point that conduces to the maximum of general vigor in the sys- 

 tem, and no farther. They may be carried further in the interest of 

 sensual enjoyment, but that is not now before us. Hence a man must 

 exercise his muscles, must feed himself liberally and give time to 

 digestion to do its work, must rest adequately all for the greatest 

 energy of the mind, and for the trying w r ork of education in particu- 

 lar. Nor is it so very difficult, in the present state of physiological 

 and medical knowledge, to assign the reasonable proportions in all 

 these matters, for a given case. 



Everything tends to show that, in the mere physical point of view, 

 the making of impressions on the brain, although never remitted dur- 

 ing all our waking moments, is exceedingly unequal at different times. 

 We must be well aware that there are moments w 7 hen we are incapable 

 of receiving any lasting impressions, and there are moments when we 

 are unusually susceptible. The difference is not one wholly resolvable 

 into mere mental energy on the whole ; w r e may have a considerable 

 reserve of force for other mental acts, as the performance of routine 

 offices, and not much for retaining new impressions ; we are capable 

 of reading, talking, writing, and for taking an interest in the exer 



