May 27, 1898.] 



SCIENCE. 



735 



ping out a line of inquiry tending towards 

 the solution of one of nature's mysteries, 

 and yet be a mere tj^ro in the art of impart- 

 ing his knowledge to a class of students. 

 It was the writer's fortune, when a student, 

 to have for an instructor a man of world- 

 wide reputation ; but, great as the man was 

 as an investigator, he was a very indiffer- 

 ent ' professor.' It has been my privilege 

 from time to time to attend lectures given 

 to undergraduates by men who, although 

 not professed instructors, stand, neverthe- 

 less, at the very forefront of their respective 

 professions ; and it has greatly interested 

 me to note how different their mode of pres- 

 entation commonly is from that followed 

 by men more in the habit of meeting an 

 audience of such a character and more 

 familiar with its peculiarities and methods 

 of thought. 



It is trite to say that teaching is a dis- 

 tinct specialty, and that to teach well is 

 the gift of comparatively few ; but the 

 fact remains pertinent, notwithstanding its 

 triteness, and is worthy of consideration. 



To return to the quotation, I would say 

 that it was written in the light of over 

 twenty-two years' class-room experience, 

 and with what I believe to be a pretty full 

 knowledge of the wants of the average 

 student. 



I cannot by any means agree with the 

 critical comment : ' Sad, indeed, if true !' 

 It is unquestionably true that every teacher 

 would find his work more easy of accom- 

 plishment could he use a text-book of his 

 own arrangement; nor is there any ele- 

 ment of sadness connected with this fact. 

 The composition of classes and the arrange- 

 ment of coui'ses cannot fail greatly to 

 modify the treatment of the same subject, 

 as presented at different institutions ; and 

 it would be small praise, indeed, for the in- 

 structor were it said of him that he stuck 

 to his text-book literally, even though such 

 book were of unsurpassed excellence. It is 



the class-room enlargement of, or variation 

 from, the text that is of real value to the 

 student, for the points thereby brought out 

 are the ones which he cannot readily secure 

 by private study. At a New York pre- 

 pai'atory school, where the methods of in- 

 struction were as peculiar as they were ex- 

 cellent, the writer remembers that the few 

 text-books permitted were mostly selected, 

 because of their poor qualities, in order that 

 criticism thereof might make a deeper im- 

 pression upon the class. Of course, it 

 would be easy to carry such a system too 

 far, especially when dealing with advanced 

 subjects ; but if the instructor be worthy of 

 his position he cannot, and should not, be 

 entirely satisfied with the matter exactly as 

 it is presented in the best text-book ever 

 written. He should have his own way of 

 presenting his subject, or else he will fail to 

 hold his classes. 



" A.n ill-favored thing, sir, but mine own," 



is a motto that might fit the method of 

 many a successful teacher of chemistry, for 

 there are but few sciences whose elemen- 

 tary teaching calls for so much good judg- 

 ment in placing the subject-matter in a 

 form easily grasped by the beginner and in 

 selecting illustrations from sources that are 

 both homely and apt. When I said that, 

 were it not for the expense of printing, a 

 man would prefer his classes to use a book 

 of his own making, I wish to be understood 

 as holding that, in order to have such a 

 book of the highest order of usefulness, it 

 must be written for his classes, and his 

 alone. For it is a fact that a man writes 

 for his private use a very different and 

 usually a much more effective book than 

 the one he dares to offer the public. It 

 would appear that books are largely writ- 

 ten to please the critics ; and if they be so 

 constructed as to pass the ordeal of ' re- 

 view,' it is entirely a secondary matter 

 whether or not the student is able to readily 



