The Purpose and Nature of Laboratory Instruction from an Historical Point of View
B. R. Siebring and M. E. Schaff University of Wisconsin-Milwaukee Milwaukee, 53201
Individual laboratory instruction a t the undergraduate level has been one of America's sienificant contributions to chemical education. Wyndham ~ i l e states s that lahoratory instruction hegan in this country as early as 1810-15 years before Liehig opened his instructional lahoratory a t the University of Giessen. The early stages of development of laboratory instruction were influenced to a large degree by the Americans who studied a t the German universities in the latter half of the 19th century. Among these educators was Ira Remsen. It was probably the enthusiasm of Ira Remsen and others like him that resulted in the firm foundation that chemistry lahoratory instruction now enjoys. Although laboratory instruction was accepted as vital in the teaching of chemistry in the eaily 1900's a period of doubt and concern hegan about 1920. The two decades between 1920 and 1940 are characterized by publications debating the question of the demonstration method versus individual lahoratory instruction.
The controversv over demonstration versus lahoratorv instruction subsided in the late thirties. overlapping withthis controversv and extendine into the seventies was the debate over what should be the nature of lahoratory instruction. In order to make some assessment of the way laboratory instruction has changed over the yearn, some represenrative laboratory manuals wereexamined. Theoldest was thesixth edition of one written by Louis Kahlenberg for a general chemistry course for engineering students in Madison in the early part of this century. The emphasisof the laboratory effort was qualitative. We are convinced that Kahlenherg's students eained much ereater exnerience in workine with chemicals-and in the manipulation of glassware ancother nonsophisticated pieces of laboratory equipment than modern students. One author in the thirties complained bitterly that students learned so little lahoratorv techniaue that thev were incompetent in the use of the rin&tand. W; don't think such a criticism could be applied to many of Kahlenherg's students.
270 1 J o m l of Chemical Education
Also we helieve Kahlenherg's students had a much greater appreciation and respect for chemicals than most modern students. In many freshman laboratories the descriptive experiment has been abandoned completely for the quantitative-type experiment. Certainly the fast-weighing modem halances have made many more quantitative-type experiments possihle--and much less tedious-for more students a t a lower level. Three general chemistry manuals from the late thirties and early forties were examined. Two of these showed the trend to fill-in-the-blank type of reports which was becoming prevalent. In comparing the Kahlenherg manual of the late teens and early twenties with the selected manuals of the late thirties and early forties, i t appeared to us that Kahlenherg accepted four principles that were abandoned in later manuals. These were: 1) That chemistry does not need to he "sold" t o the student--that chemical experiences themselves will do that. 2) That the students who take the course would be able to read, follow directions, and draw conclusionswithout being forced t o do so by a pattern of questions or detailed instructions. 3) That the students would he able to write logical conclusions in intelligible English.
4) That the laboratory instructor would he a sufficient resource for anything not given in the manual. Bv the 1940's chemistrv instructors (or at least some authors) h i d obviously lost contfdence in the last three items. students are judged unable to draw conclusions on their own: the oxygen experiment in one manual contains 42 short-answer, fill-in-the-blanks questions. The € o m of the report shows that the authors have lost confidence in students' ability to communicate in writing. Directions are extremely detailed. This seems to be the result of experiences with less able students, in conjunction with increasing use of novice laboratory instruct& (graduate students)-who cannot always he relied upon to give the necessary supplementary directions. Among the best gauges of the nature of lahoratory instruction from 1950 to the present are the Malm-Frantz manuals published by the Freeman Company. The authors found a winning combination in the first manual and stayed with it through the 25-vear life of the manuals. There were various comh&ations of 'kxperiments,different orders in which the exneriments were nresented. versions which included forms for the student reports and versions requiring independent reports. There was a gradual increase in the emphasis on quantitative-type experiments, hut the basic nature of the lahoratory manuals did not change.
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