Formal Operational-Where is it Really Needed? To the Editor: Milakofsky and Patterson ("Chemical Education and Piaget," this Journal, Feb. 1979) were probably surprised when their cognitive functioning test failed to correlate with introductory chemistry grades while correlating highly with introductory logic grades. I think the obvious explanation for this is that, contrary to what we like to believe, introductory chemistry courses don't really require students to "think". Memorizing some terminolow, . . structures, and standard pruhlem setups will serve admir~hlyfor the hulk of thecourse. Students hnvv been saying all along that this husiness that we call learning and understanding, from their perspective, is just memt,rkinr. Furthermore, the currently fashionahle devices for helpingstudents learn chemistry, such as programmed study guides, extensive problem manuals with worked solutions, computer-generated homework sets, repeatable exams, and computerized TV-tape recorder-teletype arrangements which Do Everything But Drop Peanuts Into a Food Cup (DEBDPIFC) when the student gets the right answer, seem custom-made to eet the so-called concrete-operational student through the material without embarrassing scenes where the S ~ U ~ C I Iinability I'~ at uhstract thouaht . might be innd\wtently exposed. I cannot decide iust where in our discipline the need to be, as-they-say, formal-operational really sets in. Organickers insist that reasoning is important for their courses, and certainly physical chemists feel theirs is the domain of abstract reasoning. But here again, if you ask the students, they will uf-one-voice say the necessary and sufficient survival skill is a facilitv a t massive memorization. Physical chemistry is especialiy tough since your past memorization of calculus and physics is also put to the test, and the new material you are memorizing often does not even superficially make sense. Still, veteran students will counsel those coming behind that the best approach is not to worry about what it means, but just memorize the equations (or their derivations, if the teacher is insisting that you understand where they come from) and then pretend it is math homework. Even Sommerfeld is alleeed to have commented that after the third time through thtmnodynamirs one realizes one doesn't understand it at all hut hv then in su used tu workinn- with it that the conceptual problems are easily ignored. Stephen E. Schullery Eastern Michigan University Ypsilsnti, MI 48197
Aspirin and Prostaglandin Synthesis To the Editor: In the recent, well-written article on "Medicinal Chemistry of Aspirin and Related Drugs" [J. CHEM. EDUC., 56, 331 (1979)] the following statement appears: "Recent studies suggest that aspirin can inhibit the synthesis of prostaglandins by inactivating the enzyme involved in this synthesis." In fact, the work of Roth et al. [Roth, G. J., Stanford, N., and Majerus, P. J., Proc. Natl. Acad. Sci. USA, 72,3073 (1975)l bas quite convincingly shown that aspirin possesses the unique property of acetylating the active site of cyclo-oxygenase (the enzyme which generates the cyclic endoperoxides from arachadonic acid), thereby inhibiting prostaglandin biosynthesis. Thus, this aspect of aspirin's mode of action is really well elucidated.
A Sweet Story To the Editor: It has been pointed out that in my note [55, 797 (1978)] "Synthesis of a Stabilized Semi-crystalline Polymer Foam," it is not obvious what the ingredient called saccharide copolymer is. In the experiment as I use it, this material is maple syrup or corn syrup. Robert G. Silberman State University of New York College at Cortland Cortland. NY 13045
Wlndow Cleanlng Hlnt To the Editor: I wish to suggest an alternative to the "Simple, Fast and Excellent Method for Polishing Dull Windows", 55, 681 (1978). I have been using this technique for years, and it is not only fast and simple but also very inexpensive since water is used as a polishing agent. Wet the top half of a paper towel and squeeze to remove the excess moisture that could pit the crystal. Lay on a flat surface and rub the NaCI, KCI, or KBr crystalover the damp surface, and, without lifting from the towel, work i t down toward the dry half and continue rubbing to dry thoroughly. It takes less than five seconds and your crystal looks like new. Try it, you'll like it! F r e d a W. Marks Research Technician Physics Research Armstrong Cork Company Lancaster, PA 17604
Cleanlng NMR Tubes To the Editor: I had a feeling of deja vu when I saw the note by Deluccbi and Miozzo (J. CHEM. EDUC., 56,124 (1978)) describing the cleaning of nmr tuhes. My very first publication was in the late, lamented Chemist Analyst, volume and page now long forgotten. At the time I was earning a few pennies by cleaning small vials previously used for analytical samples. All of a sudden it dawned on me that the method I was using to clean them would be an article that I could sell to the Chemist Analyst, which in those days paid for its articles. The technique, now a venerable 30 years of age, should work just as well for umr tuhes, and here's how it's done. A number of tubes are inverted in a beaker filled with cleaning solution, acetone, water or the like. The whole is placed into a vacuum chamber, bell jar, dessicator or the like. A vacuum is pulled gradually. The air in the tuhes bubbles out. When the vacuum is released, the cleaning solution is forced up inside, and, when the vacuum is again applied, the cleaning solution is drained so that one can do this over and over again. Finally, the tubes with the cleaning solution in them are removed, the cleaning solution drained and replaced with a rinse and the operation repeated. In this way dozens of tubes can he cleaned in one batch, and the job is well done. Incidentally, they can all he dried together in an oven without any further handling.
B. J. Luberoff, Editor
Ernest A. Harrison, Jr. The Pennsylvania State University The York Campus York, PA 17403 768 1 Journal of ChemicalEducation
CHEMTECH 48 Maple Street Summit, N J 07901
