778 



SCIENCE 



[N. S. Vol. XXXIII. No. 855 



iiber Algebra, by Arnold Dresden; Richard 

 and Petit's Theorie mathematique des As- 

 surances, by E. B. Wilson ; " Notes " ; " New 

 Publications." 



THE QUIZ DEMON STUATION SYSTEM OF 

 TEACHING QUALITATIVE ANALYSIS 



It is time that we are awakening to the fact, 

 that in the line of elementary laboratory work 

 there is altogether too much poor impartation 

 of knowledge. This is particularly the case as 

 regards general chemistry and qualitative 

 analysis, especially when considered from the 

 standpoint of those who expect to carry on 

 their life work in the field of engineering and 

 industrial chemistry. 



Qualitative analysis is especially subject to 

 error. Who would think of trusting to a civil 

 engineer, ignorant of the strength of the ma- 

 terial employed, the construction of a bridge? 

 Or one's child to a doctor, if cognizant of the 

 fact that he did not know the properties of the 

 drug he was administering? Is it not of as 

 great import to a chemist that he understand 

 the properties of the chemical elements, the 

 material he is using in his daily work? 



This being true, why is it that the labora- 

 tory instruction is, in many cases, left to as- 

 sistants paid the munificent sum of from $200 

 to $500 per year, with, consequently, very in- 

 different instruction ? If they are the best the 

 institution can afford, the fault can be 

 remedied, in part, by the man in charge giving 

 to his assistants all the instruction within his 

 power. 



Detail laboratory instruction is the hardest 

 of work, if rightly given, as difficult as any 

 quiz or demonstration, for what is it, if prop- 

 erly conducted, but one continual individual 

 quiz and demonstration of from two to three 

 hours' duration? It is common to consider 

 from two to three laboratory hours as equiva- 

 lent to one lecture or quiz hour. This is a 

 mistake, at least as far as the instructor is 

 concerned, for it is not a greater impossibil- 

 ity for a man to lecture or quiz for half a day 

 at a time, day in and day out, than for him 

 to give the best that is in him to a laboratory 

 class extending over a like period. I hear 



some one reply that it takes more time to pre- 

 pare for a lecture or quiz than for a labora- 

 tory period. Granted, when the laboratory 

 work is conducted as is most customary. But 

 when the instructor keeps abreast of the 

 times,' makes a thorough test of the new 

 methods, keeps track of and endeavors to over- 

 come the difficulties of the ordinary class in 

 qualitative analysis, he will devote much 

 more time to the preparation of his work than 

 a language teacher, for instance, who, year 

 after year, employs the same text in class 

 work. Tou see I am not making the state- 

 ment, " He does this," but that he should. 

 This is, of course, not possible when the hours 

 of labor are too many to allow for it the 

 requisite time. They should be shortened. 

 There should be a certain amount of time 

 spent by the instructor in his laboratory 

 " doing things." A German teacher must 

 know how to read the language. To teach 

 laboratory work correctly a man must be able 

 to do the work well himself. 



Inasmuch as I am desirous of suggestions 

 and criticisms from my fellow instructors, an 

 underlying, selfish motive prompts me to pre- 

 sent the scheme for laboratory instruction 

 employed by me. It is one which I have suc- 

 cessfully made use of during the past three 

 years and I feel it a step in advance of the 

 methods heretofore ufeed by me, and of those 

 which I have seen employed elsewhere. 



Chemical theory is based on facts obtained 

 in the laboratory. It is then true, that for a 

 thorough comprehension of the theory it is 

 necessary that the student be conversant with 

 the facts before he can understand the appli- 

 cation. I proceed, therefore, with this in view, 

 as my main objective point. 



As an essential, the instructor must see 

 every test made by the student. That this 

 may be accomplished the too often " drifting " 

 about the laboratory by the instructor must be 

 done away with. There must be system. 

 There must be known, to some one in charge, 

 what is going on in every part of the labora- 

 tory. Yet in this system, two things must be 

 guarded against in the student. First, lack of 

 independence. Second, useless waste of time. 



