May 16, 1902.] 



SCIENCE. 



779 



matter of the first importance. To be 

 sure, excess of detail must also be avoided 

 if clearness of presentation is sought; but 

 is not the present tendency somewhat too 

 violent a reaction from the methods of our 

 forefathers? One very prominent teacher 

 told me some years ago that each year he 

 takes up less material in his lecture 

 courses; what will become of them in ten 

 years more? It is the function of the 

 teacher to guide his students through the 

 maze of facts as through a crowded city, 

 that later they may find their own way 

 about ; not to whisk them around in a closed 

 trolley-car, on the globe-trotter principle. 

 One difficulty lies in the use of text- 

 books which are really only elaborated out- 

 lines of a lecture course. The result of 

 using such books is that the student's 

 horizon is bounded by the cover-boards. A 

 lecture must be straightforward and con- 

 sistent, if it is to have any value at all ; but 

 the printed page can be read over and over 

 again, and its details mastered gradually. 

 The text-book alone can provide the large 

 number of facts that must be assimilated; 

 the lecturer's syllabus is properly a key 

 to the text-book, and no more. The teacher 

 thus has a perfect right to demand of his 

 students a greater knowledge of detail than 

 he himself presents in his lectures. An- 

 other obstacle to the absorption of the 

 proper number of facts lies in the almost 

 universal attempt to treat a subject once 

 and for all. This does not seem rational; 

 nor do the student's mental limitations 

 make it feasible. To take up the metaphor 

 of the crowded city, the first efforts of a 

 good guide result in a general siirvey, 

 pointing out the topography, main thor- 

 oughfares and most important activities. 

 Then come historical landmarks, and those 

 sights which distinguish this city from all 

 others; finally a detailed study of each 

 quarter, of special industries and of prom- 

 inent people. We can follow no better 



plan in teaching a new science, giving a 

 broad survey first, then repeat, filling in 

 many new details, fiLually going over it a 

 third and fourth time, if necessary. In 

 this way the student's memory will be 

 aided rather than over-tasked ; the relation- 

 ship of parts to the whole, one of the most 

 difficult of problems to him, will certainly 

 be clearer; and the relative importance of 

 various topics will stand out prominently. 

 Then we shall avoid the necessity of turn- 

 ing out ' chemists ' whose sole acquaintance 

 with chemistry as distinguished from 

 analysis was formed in the freshman year, 

 and discontinued immediately thereafter. 

 Chemical facts ought to be systematically 

 studied each year of the college course. 



But little need be said in addition to the 

 above concerning the laboratoiy work to 

 be correlated with this plan. I should 

 merely wish to emphasize that substances 

 should be studied from the preparative, 

 analytical and physico-chemical sides 

 simultaneously; the artificial division of 

 the science for purposes of classification 

 should influence the course of instruction 

 little, if at all, during the first two years. 



THE CHEMICAL INSTINCT. 



Chemistry is a science which reasons 

 about facts through a medium of abstrac- 

 tions. "We observe colors, smells and pre- 

 cipitates, and we talk about atoms, mole- 

 cules and space configurations. The think- 

 ing chemist must continually bridge the 

 gulf that lies between fact and fancy; if 

 he can do this freely, and avoid metaphys- 

 ics, he possesses the chemical instinct. To 

 develop this instinct in the student is the 

 most important, and most difficult, problem 

 of the teacher. Aside from intuitive, in- 

 herent teaching power, I know of but one 

 plan for fostering this instinct: every 

 topic should be presented in the form of 

 a problem. Chemistry has advanced to 

 its present proportions because of the 



