If you must file reports, submit proposals, develop instructional manuals, or any type of written communication, this course will be of benefit to you. Ronald E. DlStelam, Northampton County Area Community College Bethlehem. Pennsylvania 18017
The material lends itself nicely to self-paced instruction. Since each part begins with a clear statement of objectives and concludes 'with a review of what has been covered, the amount of pre-preparation would be minimal. The cost of the series is $70 per unit or $210 for the four program set. Compared to other cassette-slide programs available in the sciences. this is rather hieh. I t would be difficult, however, if
Infrared Spectroscopy Programs Sodtler Research Laborotories. I n c , 3316 Spring Garden St., Philadelphia, Pennsylvania 19104
Lawrence J. Stephens Elmlra College Elmira. New York 14901
35mm slides1 with audio cassette1 two copies of the student notebook/$70 per unit or $210 for the four program set. 001-Bssic Principles. P a r t I "This first lesson introduces the basic principles of infrared spectroscopy and examines the single beam spectrometer. Topics covered in the first half include the electromagnetic spectrum, the infrared spectrum, molecular absorption, detection and measurement, and the types of infrared spectra. The second half is devoted to the optical and electronic components of the single beam spectrometer. These include the source of radiation, prism and grating dispersion elements, detectors, and a typical tuned amplification system." 002-Basic
Principles. P a r t 2
system performance. After a brief introduction on the concepts and advantages of the double beam spectrometer; the first section examines the optical components, detector output, and amplifier waveforms and how they differ from those of the single beam instrument. The second half introduces a set of accuracy criteria for spectra and what these dictate in terms of signal-to-noise ratio, and scan time. Finally, the relationships between these performance criteria and the physical variables of slif width and re^ sponse time are explained." 003-Quantitative Analysis, P a r t 1 "The purpose of this lesson is to develop the relationship known as the Beer-Lambert Law and indicate how to obtain accurate absorbance measurements for use in Beer-Lambert Law calculations. The first half illustrates the relationships between transmittance and concentration, absorbance and concentration, and between absorbance and cell path length. With this background, the BeerLambert Law is developed and used in several sample calculations. In the second half, the absorbance scale is introduced, baseline and observed zero corrections are discussed, and methods are indicated for estimating the baseline in scanned spectra." 004-Quantitative Analysis, P a r t 2 "This three-part lesson describes the analysis of multicomponent systems, points out techniques for improving the accuracy of inRared quantitative analysis, and discusses the effects of deviations from Beer-Lambert Law linearity. In the first section, the additivity property of absorbance is derived and employed to analyze systems of two components and n-components. Improving accuracy is seen tn involve the handline of svstematic errors. an understandine
as well as the use of working curves to circumvent these problems." Review
I t should be noted that this series is not concerned with the practical aspects of obtaining a spectrum. While the basic principles of instrument design are covered, no attempt is made to demonstrate proper adjustment of controls to optimize instrument perfbrmance. The visual component of this package is of very high quality. The speaker is easy to listen to and the pace of the presentation is also adeauate. It is too bad that all of the taDes I reviewed are marred by what sounds like someone talking quietly in the background. This could be distracting to someone using the material for self-study, although in a classroom it might not even be noticed.
252 / Journal of Chemical Education
You Can't Go Back Elementary Penguin Productions, 1043-3 South Westmoreland, Los Angeles, California, 90006. 6 minutes, 16mm, Color, Sound, 62.00, or Super-8 Silent, Color film, $39, video cassette, $64. "A non-technical film showing the irreversibility ofwents. For all students of science from beginners in grade school to advanced students of thermodynamics, and for teachers a t all levels. Shown are familiar events-friction, heat flow, melting, and combustion-backwards. A bowling ball springs suddenly into the air spontaneously; a red-hot penny cools in a flame until i t can be safely hand-held; formation of ice cubes warms surrounding water to its boiling point; soot, smoke and flame make a newspaper page. The viewer is led t o an appreciation of energy transformations and to a feeling for the implications in our ecological crisis of the Second Law of Thermodynamics. An extensive set of such questions with answers is included." Review
Most chemistry teachers do not make sufficient use of the unique capabilities of films, and are understandably skeptical of the claims made for them. They should however give this short film a try. It is entertaining and it makes clearly its point on the second law of thermodynamics. Best of all i t will make you and your students think, and it can be effectively used to initiate a disc"ss~"~.
It is clearly aimed a t thermodynamics classes in the sense that scenes are selected upon which entropy calculations can be made.
This reduces the human element to a minimum, but not so far as to eliminate the dramatic effect. I personally almost jumped the first time I saw fingers take hold of a penny just removed from the flame. Nevertheless the distributors are correct that the film can be effective for audiences from grade school students through thermodynamics professors. Pre-school children who can't read will miss the point, but second graders can explain it after viewing it once. This is an effective film, well done. You will probably, like me, want some things done differently, and the questions with the film encourage thinking about what additional scenes would be useful. However we would not feel this way about i t if i t were not very effective as it stands. If there were more short films of this quality our excuses for not using films in upper division classes would evaporate. The film comes with a list of 51 questions. The distributors state, "The film is primarily to stir up interest and to amuse and is not meant to be completely independent of the questions." I would advise you to allow the film to stir up an interest, and then proceed in whatever way is appropriate to your particular class situation. Do not destroy that interest by spending any substantial time with the questions. They contain some interesting ideas that can be added to a discussion, but the question form is not necessarily the best way to do this. Computing approximate values of S t o u t for some of the scenes photographed could be a homework assignment, but not necessarily any better than problems from the textbook. Fortunately the film is not limited to use in a particular way or with a particular set of questions. Reed A. Howard Montana State Univerrily Boreman. 59715
