DISCUSSION LYMAN J. WOOD,ST. LOUISUNIVERSITY, ST. LOUIS, MISSOURI
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It occurred to me while listening to this excellent paper that in the main one type of school is considered while most of us have to do with another type of school. At Princeton the entering students are carefully picked and the registration is large while a t many schools i t is obligatory that all. students who come with a high-school diploma be accepted. Also in most' schools the registrati:n is much smaller than a t Princeton. It is quite clear then that what may be quite satisfactory a t one type of school may be wholly inapplicable in the other. My own notion of the case is that while Prof. Funnan's suggestion of two classes in the course in qualitative represents the ideal, in many schools the plan is not practical because of the smaller,registration. For the student who majors in chemistry the second course would be very valuable hut so many required courses are included in the curriculum that few students could find time t o take the second course in qualitative before his graduate course, where in my humble opinion i t might well be placed. At St. Louis University we do, to a certain extent, what Prof. Furman does by offering a second course. Qualitative is given during the second half of the first year and the same teachers continue with the class throughout the year. By the end of the first semester the superior student has been recognized and qualitative unknowns issued to him are markedly more diicult than those issued to the average or inferior student. What is believed to be a justification for this unequal treatment of students has been laid down by the author in previous publication^.^ See Tms JOURNAL, 3, 1313-20 (Nov., 1926), andSch. Sci. Math., 27,919-25 (1927).
There were two or three points in Prof. Furman's paper which appealed to me as being particularly noteworthy. The method of informing the students of his mistakes when an especially bad report has been made is one that I do not believe is generally followed. Frequently students have come to our attention who have spent an undue amount of time repeating an unknown when perhaps more knowledge would have been gained if the student's mistakes had been pointed out and a new unknown issued. An especially praiseworthy point brought out in the paper under discussion is to be noted in the teaching of the sensitivity of various tests. Every teacher has no doubt realized many times the lack of an appreciation of the relative sensitivities of the various qualitative tests on the part of his stndents. I believe also that the teaching of students to judge relative amounts in an unknown is to be3ighly commended. Prof. Furman did not mention the use of the spectroscope in qnalitative analysis. The use of this instrument seems to me of great importance, not only because i t is an aid to accurate work but also because the class almost unavoidably gains more or less of an appreciation of the physics volved in spectroscopic analysis. In our laboratory the spectroscope burner and electric light bulb for reading the scale are all fastened to a heavy wooden base. The width of the slit is also adjusted a t the beginning of the course and the adjustment nut removed. The outfit is thus practically fool-proof. No attention is necessary save an occasional cleaning of salts out of the Bunsen burner. A chart of the calcium, barium, strontium,, potassium and sodivm spectra as they appear when observing them by means of this particular spectroscope is posted nearby. As a part of the final examination a laboratory unknown which must be solved by the aid of the spectroscope alone is issued.
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