TRADITION VERSUS EFFECTNENESS HENRY J. LONO,GREENVILLE COLLEOE, GREENVILLE, ILLINOIS For a number of years the writer, with many other chemistry teachers, has felt that the laboratory work in general chemistry has had a low efficiency, judged by its teaching value. It is a deplorable fact that in an average class the good student can do the most of the thinking for the poor one. The latter may never learn more than to stumble step by step through a procedure as he would read and follow a recipe from a cook book. The incident of a student in a certain university accidentally turning in a notebook of a previous year instead of her own is a clear illustration of the fact that there often is not as great originality in writing experiments as is desired and that a notebook may teach more penmanship than chemistry. Words are almost too weak to describe the listless, unconcerned, helpless, "don't care" attitude of an uncomfortably large per cent of beginning students. What general chemistry teacher is not familiar with the student viewpoint suggested by the following? If the student decides to hasten the process of weighing with the more delicate balance by picking up the weights with his fingers, he seems to consider that if the weights do happen to become corroded there is no way of discovering who did i t in such a large group. And no doubt there are others who do it, too. If, in weighing a sample on the pans of a rough balance, a part of the substance rolls off the paper to the shelf or floor, what does it matter? The balance pan is entirely too narrow, anyway, Or, if the test tube breaks and the contents spill over the table top, why wony? Isn't it the janitor's job to look after such things? In case the glass stopper of the reagent bottle happens to be a little tight, instead of learning how to coax i t out carefully, i t is struck with an iron ring and broken off. But no bottle in such a condition should have been upon the shelves. And if he carelessly spills a few drops of hot, concentrated sulfuric acid on his neighbor's sleeve, or his instructor's laboratory coat, he glances up with a sort of apologetic air, as much as to say, "That is all right, I didn't need it anyway for we have plenty more." These, and an almost infinite number of equally wooden actions of elementary students, nearly cause an instructor to utterly doubt his ability to teach proper attitudes or to develop the scientific mind and viewpoint. It is with the thought of trying to arouse this too large percentage of students from their somnambulistic tendencies, and to make the laboratory work more than a "cook book" and "copy book" exercise, that in Greenville College we are attempting a somewhat revolutionary experiment. It seems that since the days of phlogiston, chemistry experiments had to be formally written in order to constitute creditable work. But the fact that it has always been done that way is not sufficient justifi1642
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cation for its continuance. Why write them if the energy required therein, expended elsewhere, would have a greater teaching value? Instead of requiring a formally written notebook in the usual way, we decided to give a quiz on the day's experiments a t the end of each laboratory period. It should be stated that we claim no originality in the matter of the quiz a t the end of the laboratory period on the day's work, for it has been used, to some extent a t least, in organic chemistry classes a t the University of Kansas. The students are left a t liberty to make their own notations and equations in the blank spaces and pages of their books, which they freely do in order to get the information which they themselves want. Since we are using a combined text and laboratory book, it is easier to correlate the two phases of the course. At first it seemed likely that we could not expect quite as much work to be done as before, if the students were required to have it prepared for a quiz inside of the one, two-hour laboratory period. This, however, does not seem to be true, for the extra urge of being held immediately accountable for the facts studied appears to rather quicken muscles and intellect alike. If the confidence of the students is kept by carefully making the assignment of such a length that they can adequately cover it in the required time, they all seem to recognize a definite goal toward which they are working in a particular laboratory period. In order to save time and energy for student and instructor, the new type of quiz is used. From ten to twenty specific and representative questions are given which may be answered quickly in one or two words or formulas. The student numbers the questions and, of course, writes nothing except the answer. The name of the student is signed and the papers are exchanged between the members of the class. The person receiving the paper now writes "Graded by John Doe" across the bottom of the paper, and draws a circle around it so i t can be seen readily. The fact that a student signs his name as having graded a particular paper seems to make him quite conscientious in grading it accurately. The answers are then quickly read by the instructor and checked by the student and the papers graded. The papers are collected and may be roughly checked over by the instructor if desired. This entire exercise can be taken care of inside of ten or fifteen minutes a t the end of the laboratory period. The following is a list of typical questions on the topic of "Hydrogen Sulfideand Its Salts," ten or fifteen of which will fairly adequately cover the subject, and can be given in the time allotted: 1. In our laboratory preparation of hydrogen sulfide, write formulas of the two substances used in the generator. (FeS, HCI) 2. Give formulas of the substances produced. (FeClr, HIS) 3. Give the color of hydrogen sulfide. (Colorless) 4. Is hydrogen sulfide appreciably soluble in water? (Yes)
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5. Is hydrogen sulfide lighter or heavier than air? (Heavier) 6. Does hydrogen sulfide have any odor? (Yes) 7. Is hydrogen sulfide acidic or basic in properties? (Acidic) 8. I n general, t o what group of compounds would you add any reasonably strong acid t o produce hydrogen sulfide? (Sulfides) 9. Whenever silverware turns black i t constitutes a test for what element? (Sulfur) Or, a fruit jar rubber was found in contact with a silver knife on which was a circular black ring. This shows the presence of what element in the ring? (Sulfur) 10. A paper moistened with a solution of a soluble lead salt on exposure t o an unknown gas turned black. What was the gas? (H.S) 11. I n the burning of hydrogen sulfide what product may be obtained which is a gas a t room temperature? (Sulfur dioxide) 12. I n burning hydrogen sulfide, what product may be obtained which is a solid a t room temperature? (Sulfur) 13. I n burning hydrogen sulfide what product is formed which is a liquid at room temperature? (Water) 14. When hydrogen sulfide is bubbled into a blue vitriol solution, give the formula of the precipitate. (CuS) 15. What color is the precipitate in No. 14? (Black) 16. What color is zinc sulfide? (White) 17. What color is cadmium sulfide? (Yellow) 18. Is a water solution of hydrogen sulfide highly or slightly ionized? (Slightly) 19. Is hydrogen sulfide a good reducing or oxidizing agent? (Reducing) 20. What is the valence of S in the sulfides? (Negative two)
The above procedure has been tried for approximately a year now on two different classes of general chemistry students of about thirtyfive or forty in each class; the laboratory group, itself, consisting of approximately twenty students. I t is early to predict all the results, either good or had, as compared with the former method. I t is very refreshing, however, to note how spontaneously the students come to their instructors with their questions. Where formerly only that small group of questioners would venture unless strongly urged t o do so, now nearly all seem to feel some impetus to come. The students, themselves, stzte freely that they are learning more during their laboratory period than formerly. The fact that both groups were started for a few weeks following the usual plan, gave them some basis for comparison. It is our opinion, also, that the grades from the examinations on the textbook work as a whole are being decidedly benefited by such a method. While it means somewhat more work a t the time for the instructor, yet this is offset by the fact that the tedious reading of a formal notebook on week-ends is decreased to a delightful minimum.
