34 THE POPULAR SCIENCE MONTHLY. 



the pupil must be actually in possession of principles previously ex- 

 pounded for which he may be called upon at any time. It is simply 

 impossible for a person to be absent and neglectful for a time in his 

 study, and then come into the class-room to make a brilliant show on 

 an intermediate fragment of the subject. He can be too easily exposed 

 as a humbug to attempt it a second time. Moreover, thus to force him 

 to do the work as he goes along is the greatest favor one can do for 

 the pupil ; and the usual cramming before the examination becomes, 

 in reality, a general review, which is very useful in bringing him to 

 see the connection existing throughout the whole subject. 



4. If the class is too large to reach each member as often as the 

 instructor might wish in the above method, there is one device which 

 is more or less useful. At the beginning of the hour let him write a 

 question upon the blackboard, to be answered by each one in writing 

 within the first fifteen minutes. The attempt to write out an explana- 

 tion clearly, without hint or clew from the instructor, will reveal to 

 the best student the deficiencies and gaps in his knowledge. Each one 

 will then have the keenest interest to know what is considered a satis- 

 factory answer to the question. At the next exercise of the class, the 

 instructor can read some good and some bad answers, point out the 

 general mistakes, and advise them for the future. No exercise can be 

 better than this in cultivating the habit of careful expression, and in 

 learning how to make a clear and pointed exposition of a subject in a 

 brief space of time. This practice tends to secure the accuracy which 

 in the oral discussions is made second to fluency and readiness. 



5. Since the chief work of the class-room is not to enable students 

 to discover principles, but rather to understand and apply them, prob- 

 ably the most useful method of interesting a class is to present to 

 them by extracts from the newspapers of the day bits of fallacious dis. 

 cussions which may come under the head of the subject in hand, and 

 ask for criticism and discussion of them. The appositeness of a timely 

 topic is peculiarly valuable for such purposes. In fact, the practical 

 matters of our own country will never fail to excite a lively interest 

 in almost any class ; and through this interest the teacher can find a 

 way of leading men to study principles more carefully. A national 

 or State campaign is very likely to furnish an instructor with a plenti- 

 ful supply of extracts for discussion by his class. The learner in po- 

 litical economy is not hindered by the same disagreeable obstacles, as 

 impede the medical student, in finding subjects on which to put his 

 learning into practice. 



6. Many minds are unable to keep hold of an abstraction, or gen- 

 eral principle ; or they have been untrained in making nice distinc- 

 tions between ideas or definitions. Just as in beginning a strange lan- 

 guage, when words of widely different meaning have a similarity to 

 the untutored eye, the distinctions do not make much impression. So 

 it is in regard to ideas and definitions in political economy. There- 



