mmething new from the bwt During t h e p a s t two years, THIS JOURNAL has devoted two issues t o t h e chemistry of a r t (April 1980 a n d April 1981). Imolied therein is t h e use of t h e sense of sieht in chemistrv. I n rairness to some of t h e o t h e r senses w i t h i e s p e c t t o chemistry, t h i s month's S o m e t h i n g New from t h e Past will be devoted to the senses of t a s t e a n d smell. T h e articles t h a t have been selected for inclusion here a r e those t h a t can h e used by teachers of beginning chemistry t o "enrich" their backgrounds. I n addition to articles on theory, you will find articles . . of pragmatic value in classroom work, i.e., experiments you c a n e a t a n d smell.
"The Physicochemical Aspects of t h e Sense of Taste," Lloyd N. Ferguson and Aetius R. Lawrence, J. CHEM. EDUC.,35 [S], 436-443 (September 1958). The authors of this article state, "Deep aesthetic enjoyment is experienced through the sense of taste, and there are those who live to eat." In addition to the many valid reasons for studying about the sense of tastecited by the authors, they say that "something may he learned about the way chemicals stimulate biological activity." They write of the complexities involved in the academic study of the gustatory sense. Early in their article they describe the physiology of the taste aeain. Taste oualities are discussed with examoles that can he used, and jomr rhnr should nor he used, r g . , lend nretnte tweet,. Taste trends nre listed with respect to tnerenamg molerulsr we~shts and ionic mobility. The familiar use of phenylthioearhomide (PTC) is cited showing that less than 30%cannot taste it, hut more than 70% find it extremely lhter. Structure-tnrw amelationb are d e s c r i t d in a m e detail, as is the "lock and key" nurim irf hrologicnl activity and receptor sites.
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Jumping 20 years, the next article describes some of the latest uses of instrumentation to determine the chemical constituents of odoriferous foods-mass spectrometry coupled with gas chromatography. Another good article on the subject is "Flavor Research," by Roy Teraniski of the Western Regional Research Center, US. Department of Agriculture, American Laboratory, 51-56, June 1919. If it is still available, try to obtain "Exploring Your Sense of Smell," Science Study Aid Series, US. Department of Agriculture, Western Reeional Research Laboratow. ,. Berkelev.. California. John Boeschen. .Jd~nK. ,\moore. and Dame (;. (iuadagni. Thir study aid gives excellent clasrnum activities that are intt.rdi+ciplinaryin nature. "Current Ideas o n the Chemical llasis 01' Olfaction." William R. Roderick, J. CHEM. EDUC.4 3 [lo], 510-520 i o c o t o b e r 1966). The author saw. "The relationshio between chemical structure and physical and hithgaal nrti\,itiei have Iml: mtrrgued the mmdc of chemist*. Thcdcvelr~pmentof theories on strurture-actiwty rclatim5 lS.4Hl requiwda large nun~brrul d a ~ and a hwwe h d ~ been 5 1 until ~ the present century, when the number of new compounds synthesized has grown exponentially." He also says that "a theory can be develo ~ e which d accounts for the known physical or hialo~icalactivity in terms of molecular structure, enahlesp&diction of theactivity of new compounds, and provides direction for the synthesis of compounds with desired activities." Roderick's paper is a superb resource far the chemistry teacher unfamiliar with the chemical basis of smells and smelling. There are msny "interest-catching" activities that can be developed using Roderick's compilation as a basis. This Editor has used the idea of the odor-bar for such an activity to introduce the general public to the fascinations of chemistry. See the following article.
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Edited by:
JOSEPHS. SCHMUCKLER Chairman of Science Education Temple University 345 Riner Hall Philadelphia. PA 19122
"The Franklin Institute Chemistry Exhibit," Irwin Siegelman a n d Joseph S. Schmuckler, J. CHEM. EDUC., 38 [12] 597600 (December 1961). A list of esters with some familiar odors can be found in "Fragrant Esters," J. B. Capindale, CHEM 13NEWS, (February 1977). Do not ovedwk the possible use of Aldehydes, i.e., cinnamaldehyde, etc. Natural products-most of which are very familiar and all of which are volatile-serve as the basis of the next article on smel!s and smelling. "The N a t u r e of Essential Oils, Part I, Production." Frances S. S t e r r e t t , J. CHEM. EDUC., 39 [4], 203-206 (April 1962). "The word essential oils undoubtedly originates from the Latin quinta essentia (quintes-sence), the fifth element, the essence of things. Alchemists believed essential, ethereal, or volatile oils to be the most condensed form of the individual characteristics of the plant or drug. Since antiquity man has been mystified and intrigued by essential oils and has made ereat efforts to obtain them. Todav as a result of man", vears of research these oils have become trulv indisoensable and , 01 liie. I)uring tl~ecuurueofaringlcday, from the rsrrntiul toour first day of existrnrr tc, the last, ewry living person in this emmtry uses or consumes many of these substances. They have a variety of applications in almost all industrial and consumer products, from rubber baby pants, food, and toilet preparations to embalming fluids. Essential oils are used mostly for theirsensory quality, but often also for their antibacterial and antifungicidal action. They are mainly of botanical oriein. comoosed of the oreanoleotie orineioles which rmtrihutp the ~ O nnd T f l n w r of rhp nromalic plant material: thew are only very 1Pw e ~ c e p l h mof mimnl orimn, such m musk, w e t , nnd
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Stcrrctt lirts well w e r llKl important e-sential d r , msny 1 8 f uhich are familiar. He diwuuscs three ba5ic terhnlques uf productronsteam distillatiun, exvrrrsim, and extraction. He d e s ~ r h e sthe "synthetic oils"-the aromatics and the isolates--specific fractions from the distillation of natural oils containine one chemical .. eenerallv .. compound i n mow or lrss i,onwric mixture.e y..citral, pinene. linalod, citroncllnl, snfrol, and rug, nul. The follow-up nrr~rlr,Part I I I "Chemical Cunstiturntu, Analysir." appears in the May 1962 issue Also recommended is the following article: "Perfumes a n d the A r t of Perfumery," Nancy G r a n t a n d Renee G. Naves, J. CHEM. EDUC., 49 [El, 526-528 (August 1972). "Theory of Sweet Taste," Walter Guild, Jr., J. CHEM. EDUC., 49 [3], 171-173 (March 1972). The author says, "Various attempts have been made to rationalize the chemical basis of the taste sense. The purpose of thisarticle is to review the studies of R. S. Shallenberger, New York State Agricultural Experiment Station, Geneva, New York, and his colleagues in order to acquaint the reader with the most recent approach they have taken to establish the molecular features common to compounds which taste sweet." "Sweet Organic Chemistry," Lloyd N. Ferguson, e t al., J. CHEM. EDUC., 55 [5], 281-285 ( M a y 1978). Ferguson, working with young students as part of an N.I.H. Research Training program attempted "to examine some observed structure-taste correlations, and to explore one or two generalizations which might help elucidate the mechanism of taste stimulation."
Volume 59
Number 7
July 1982
619
See also: "Comparing Sweeteners," Chemistry, 17-18 (October 1976);and "Molecular Aspects of Sweetness," Chemistry,27 (duly1 August 1977). The following are experiments you can eat! Before this Editor is criticized for suggesting eating in lab, he urges the readers to look a t the literature cited! "Making Baking Powder Biscuits, A Practical Experiment on Hydrolysis" of Salts," R. G. Ramey, J. CHEM. EDUC., 39 [I], 363-364 (July 1962). "Gimmicks for Mid-Year Motivation, Provocative Opinion," Richard C. Adams, J. CHEM.EDUC., 49 [a], 530-537 (August 1972). "Pre-Vacation Experiment: The Effect of Temperature and Torsion on the Structure of a Saccharide," Linda Kay Ford, J. CHEM. EDUC., 54 [S], 550 (September 1977). "Synthesis of Stabilized Semi-crystalline Polymer Foam," Robert Silberman, J. CHEM. EDUC.,55 [12],797 (December 1978). "Baking Out Chem Lab Doldrums,"Lloyd D. Remington, The Science Teacher, 39-40 (December 1972). "The Chemistry of a Baking Cake: Eating Metric," Constance Marino and Joseph S. Schmuckler, Science Activities, 17 141.30 1980). ~ , . (NovemherIDecemher . "Another Christmas Kxperiment," Glen Lo\,eridge, C'HKM 13.Yb.'IV.S, S rNovemher 19751. "Salad Bowl Biology," Emmett L. Wright, The American Biology Teacher, 41 [Z], 80-85 (February 1979).
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Journal of Chemical Education
And Finally For those of you who were fans of W. Tom Lippincott's editorials during the years he served as editor of THIS JOURNAL, you probably marveled, as I did, as to his breadth and depth of knowledge. I feel this editorial-"The Preparation and Administration of Aphrodisiacs," J. CHEM.EDUC.,48 181, 491 (August 1971)-is quite fitting for this month's topic of Something New from the Past. Lippincott begins his editorial with a fable: "Some years ago, long before the rules of love handed down from Mt. Olympus by Venus were redefined by the liberated female, a chemistry graduate student, interested in teaching as a career, visited a wise old alchemist seeking oreoaration and ad" his advice on the . . ministration of aphrodisiacs. The alchemist, desiring to learn what lay behind this interesting request, asked the student what he hoped to do with this knowledge should it be revealed to him. The student replied that he felt it would beinvaluable to him in his teaching, and that it offered almost unlimited opportunities for research projects of unusual promise. The first part of this response intrigued the alchemist and the second part amused him; and, having concluded that the student possessed a combination of qualities worthy of encouragement, he gave him the following instruction. 'There are five classes of aphrodisiacs, based on the type of physiological response desired; there are five types of situations in which they may he administered with impunity, and there are five varieties of subjects that can be expected to give measurable responses to them.' " From his literature research Lippincott describes their physiological responses, when they should he used and with whom they may be used. He goes on to give the chemical compositions of the aphrodisiacs. For more details, refer to p. 491, J. CHEM. EDUC.,(Aug. 1971)!
