JOURNAL OF CHEMICAL EDUCATION
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MOTION PICTURE DEMONSTRATIONS I N ANALYTICAL CHEMISTRY' RALPH A. JOHNSON University of Illinois, Urbana, Illinois
C H E M T S T R Y teachers must not only be good chemists, but specialists in commuuications as well. Verbal communication indeed has its shortcomings, and these are most noticeable in presenting laboratory techniques. Words are inept for describing operations which require timing a n d ~ g n a t i o n . Here a demonstration by a skilled tee n Ian 1s an unexcelled medium of commuuicatiodc The heed for demonstrations in analytical laboratories is particularly great, but this order is difficult to fill. A good demonstration requires time for preparation and skill in execution. Furthermore, "live" demonstrations of techniques can be effectively given to only a handful of students a t a time. To find personnel for an adequate demonstration program is difficult where large classes are involved. Motion pictures appear to be our best medium for demonstrations to large audiences. With proper photography, finest details can be shown to the largest classes. Also, a motion picture can be made "foolproof." Mistakes and false moves can be cut out ahead of time. The movies are ready to go a t a moment's notice, thus practically eliminating the necessity for time-consuming preparations. A movie standardizes techniques. It decreases the possibility of teaching inefficient or erroneous techniques. It also leads to uniformity within a class. However, because it ignores many other techniques and implies that the technique shown is the only ac-
cepted one, it may be misleading. Among professional chemists, a variety of techniques may he found for any operation. Further, any basic technique is subject to modification upon occasion, depending upon the experiment. Standardization should not be so rigid that modification cannot be readily and gracefully made when necessary. Because a film can efficiently show only a few basic operations, it devolves upon the instmctor to expand his student's knowledge and judgment of techniques. The art and science of producing analytical technique films is three-sided: photographic, commuuicative, and chemical. The photographer has special problems. He must be careful of background and must provide adequate lighting. Close-ups, such as those of a balance pointer or an asbestos mat, require special attention. Whether or not the audience will really see the details as intended depends upon the care and judgment of the photographer. There are a number of tricks to visual communication that enable audiences to get the most from the medium of picture film. For example, an over-the-shoulder shot shows action, as one who was actually carrying out the operation would see it. When viewing such a shot, a student in his mind, projects himself into the action; he carries out the operation. The photographic and communicative aspects of film making are su5ciently complex to warrant the Presented a t the Conference on the Teaching of General and services of specialists in these fields, if possible. The Analytical Chemistry at Oklahoma. A. and M. College, June 13, task then remaining for the chemist is the critical choice of techniques to be shown and proper execution 1952.
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of them. Also, the chemist contributes via the sound track explanatory notes as the story unfolds. Much of the verbal explanation is best given by the instructor in the classroom or laboratory situation. The film narrator may conveniently open the way for these comments by referring the audience to the instructor for details a t various points in the film. Demonstration films can contribute to analytical instruction with subjects other t,han classical laboratory techniques. There are a number of subjects which are increasing in importance and making strong bids to be included in already crowded course curricula. Notable among these is instrumental analysis. Films portraying the principles and applications of modern instruments promise to be an efficient and economical way to introduce the subject in elementary courses. Microorganic combustion analysis could also be demonstrated by film. Procedures which are long and t,edious could be shown with the aid of time-collapse technique. Some beginnings have. been made to produce films for demonstrating analytical laboratory techniques. The new tool must yet he tested in the fire of experience. From the tests should come not only improvements, but expansion into a motion picture program adequate for modern analytiral curricula.
Acknowledgment
The author wishes to acknowledge the very considerable contribution to this paper by many discussions with Mr. Lewis V. Peterson, Division of Visual Communications, University of Illinois, Urbana, Illinois. List of Analytical Demonstration Film. and Source of Availability
(1) Use of Analytical Balance, Audio-Visual Aids Service, Westbrook Hall, University of Minnesota, Minneapolis 14, Minnesota. (2) The Analytical Balance, Lewis V. Peterson, Gregory Hall, University of Illinois, Urbana, Illinois. (3) Techniques of Gravimetric Analysis, Lewis V. Peterson, Gregory Hall, University of Illinois, Urbana, Illinois. (4) Formation and Handling of Precipitates, M. G. Mellon, Chemistry Department, Purdue University, Lafayett,e, Indiana. (Not available for distribution.) A rather complete listing of films for chemical education is available from t,he American Chemical Society.
