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DECEMBER 2001

Fragrances and Smells This chemistry gets personal! The Feast of Luminol KING MIDAS A simple spray casts a revealing light on crime. Chemists analyze the leftovers. Question From the Classroom By Bob Becker

1 2 3 Q. Do ducks get cold feet?

A. If you have ever watched The fact is that the ani- temperature (42 °C), mal’s blood supply has then lose a huge a duck paddling its way No heat Maximum through frigid water on a already been cooled consider- amount of heat to the exchange heat winter day, this question may ably before it ever reaches the cold water as it exchange have occurred to you: Why feet. There’s not much energy passed through all Some heat exchange don’t ducks get cold feet? The left in the webbed feet to be the small capillaries, answer is actually quite drained away by the high heat- delivering its oxy- simple. They do. In fact, their capacity water. Likewise, the gen to every cell in feet and the blood inside them returning blood has already the duck’s foot. The get nearly as cold as the been warmed before it re- blood would then surrounding water. How can enters the body. As a result, travel back toward they stand it? Perhaps they virtually no energy is wasted the heart at 2 °C, Heat lost through feet to icy water have few nerve endings in as the duck’s body maintains and, assuming the their feet, or perhaps, they its internal temperature while duck could sur- and a little less energy needed have simply grown to LIKE paddling through icy water. vive this shock, it would to rewarm the blood. This plan having cold feet! How does the duck man- require an enormous amount would be a definite survival A better question to ask, age that? It all has to do with of energy to warm the blood advantage for any duck with however, is how do they sur- something called countercur- back up to 42 °C. such a circulatory system. vive it? How can ducks—or rent heat exchange, and it Now let’s make one small Actually, the duck swim- any other warm-blooded ani- relies on the extensive net- adjustment. Let’s place the ming in icy water operates on work of veins and arteries in vein and artery closer togeth- a fine-tuned version of this mals—afford to lose that ILLUSTRATION BY CESAR CAMINERO much heat to their surround- the duck’s legs. A duck’s body er, as shown in the second heat exchange plan. The third ings? Here’s where the story temperature runs about 42 °C pattern in the figure. Now pattern in the figure shows gets intriguing. It turns out (108 °F), and the water in there is a way for transferring how the blood vessels in a that they don’t! You might which it is swimming is often some heat from the outgoing duck’s legs are arranged. expect that those webbed feet just above freezing—say 2 °C 42 °C blood to the returning Veins and arteries are finely with all their exposed surface (35 °F). Suppose the duck just 2 °C blood. As the outgoing divided and interwoven so as area would allow for all sorts had one main artery running and incoming blood pass each to ensure maximum contact of heat loss. And you would from its body to each foot, other, the cold blood warms and maximum heat transfer also think that a lot of pre- and one main vein, completely up and the warm blood cools between the outgoing warm cious energy from the metab- separated, running back to the down. Even if the exchange blood and the returning cold olism of food would be spent body. results in only a few degrees blood. With such extensive reheating the chilled blood As shown in pattern 1 in of temperature change, there contact between veins and flowing back into the duck’s the figure, the blood would would still be a little less heat arteries, the warm blood leav- body. enter the foot at the full body lost to the surrounding water ing the body cools to nearly 2 °C as it travels down the

tus for federal income tax purposes leg. Likewise, the cold blood Statement of Ownership, Management, and have not changed in the past 12 leaving the foot warms up to Circulation for ChemMatters Magazine months. 45,000 copies of each maga- nearly 42 °C as it travels up zine issue are printed. Average circula- tion during the past 12 months was the leg. ChemMatters is published quarterly by the 30,621. Circulation closest to the filing date was It works great! By this coun- American Chemical Society, 1155 16th St., NW, 14,845. There are no paid in-county subscriptions, tercurrent heat exchange, the Washington, DC 20036. Both the office of publica- no sales through dealers or vendors, and no other tion and the general business office are at USPS mailings at other classes. There is no free duck loses only a minimal American Chemical Society, 1155 16th St., NW, distribution of ChemMatters. During the past 12 amount of heat from its feet, Washington, DC 20036. Editor: Michael J. months, an average of 14,379 magazines per issue and it needs only a minimal Tinnesand; Managing Editor: Helen G. Herlocker. were not distributed. For the most recent issue Owner: American Chemical Society. There are no (October 2001) 30,155 were not distributed. This amount of energy to warm the other known bondholders, mortages, and other statement was filed according to Section E216.3.0 blood back up. Our refrigera- security holders. The purpose, function, and non- of the USPS Domestic Mail Manual on October 1, tors and heat pumps should profit status of this organization and its exempt sta- 2001, by Michael J. Tinnesand, Editor. work so well.

2ChemMatters, DECEMBER 2001 ¨

Vol. 19, No. 4 DECEMBER 2001 DEPARTMENTS Question From the Classroom 2 Do ducks get cold feet? Well, maybe this isn’t the question on everyone’s mind, but it is curious how ducks can paddle around in near-freezing water without so much as a shiver! ChemSumer 8 How We Smell and Why We Stink Let’s be blunt. Humans are among the smelliest creatures on the planet, a fact not lost on manufacturers, who turn out hundreds of products designed to keep our natural aromas in check.

MysteryMatters 12 PHOTO BY MIKE CIESIELSKI Luminol—Casting a Revealing Light on Crime FEATURES Sprayed with luminol, the suspicious stains glowed with an eerie King Midas: Leftovers From his Last Feast 4 blue luminescence. What once appeared as an ordinary home No longer even remotely edible, these 2000-year-old was now believed to be a crime scene. leftovers presented analytical chemists with an interesting ILLUSTRATION BY DAN SHERBO challenge. They not only figured out the ingredients, they Chem.matters.links 16 even came up with the recipes. Link to some ancient recipes for serving up your own royal feast. Trolling the Seas for New Medicines 6 All living things trace their origins to the sea. Now drug researchers find that the oceans contain chemical treasures for curing illnesses and maintaining health. COURTESY OF AMY WRIGHT Hypothermia—Surviving the Big Chill 14 For cold that goes beyond a frosty morning, the human body resorts to some effective strategies to stay alive. TEACHERS! FIND YOUR COMPLETE uzzler TEACHER’S GUIDE FOR THIS ISSUE AT CM P www.acs.org/education/curriculum/chemmatt.html. How is the top of your head like a duck’s foot? Find the answer in this issue of ChemMatters!

COVER PHOTO BY MIKE CIESIELSKI

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ChemMatters, DECEMBER 2001 3 By Steve Miller

n 1957, a team of archaeologists working in central Turkey found a large tomb enclosed in a 150-foot-tall mound of stone, soil, and clay. Its extraordinary size, location, and rich array of Iburial goods all pointed to one thing. It was the burial place of a king. At first, they thought it to be the tomb of King Gordius, an ancient king of this region called Phrygia. But as they explored the tomb, they realized it was the tomb of his son—the legendary King Midas! Buried with the ancient king’s bones, they found 18 large pottery jars and more than 100 serv- ing and drinking bowls. They were excited to find that the bowls were not empty! Instead, they were still filled with the remains of a funeary feast fit for a king. But what was once a fine meal was now nothing more than spongy brown masses and yellowish residues with dark, glassy-like inclusions— all leftovers from a meal that had been sitting around for 2700 years. Judging from the number of serving dishes, it had been quite a banquet! At least 100 people attended King Midas’s funeral, sharing in the meal. As was customary, after the funeral feast, much of the food was left in the tomb before it was sealed—perhaps as provisions for the king’s journey into the afterlife. The archaeologists collected the remains of the feast—about seven pounds of residues that were clearly no longer edible—and delivered them to the Museum of Archaeology and Anthropology at the University of Pennsylvania in Philadelphia. There, chemists determined the material to be organic, containing carbon, nitrogen, and other elements common in living things. But that was about all that they could determine in 1957. The technology for more detailed analyses had not been

PHOTO BY MIKE CIESIELSKI developed. In 1999, Patrick McGovern, a research scientist at the museum, whose specialty is molecular archaeology, decided to take another look at the food prepared for the Phrygian king’s mourners. Using state-of-the-art analytical methods, he still found the task of identifying the source of the residues to be challenging. Reading the leftovers Tasting was out of the question for these ancient leftovers. Instead, McGovern’s research team used liquid and gas chromatography (see sidebar on next page) to isolate individual chemi- cals from the mixtures in the ancient food bowls. Once the chemicals were separated, specific compounds were identified by infrared and mass spectroscopy. (See “Drug Detection at the Olympics—A Team Effort” in the December 2000 issue of ChemMatters.) The researchers knew that if they could identify many of the compounds, they could use historical descriptions of ancient food sources to figure out the ingredients used to prepare the feast. The spongy brown mass was probably the remains of the main course of the meal—a spicy stew. Meat fat contains long molecules, called fatty acids, each consisting of a chain of carbon atoms with a carboxylic acid group at the end. The many kinds of fatty acids differ in their carbon chain lengths and the number of carbon–carbon double bonds that they contain. The brown material in the serving pots contained large amounts of palmitic acid and stearic acid with somewhat smaller amounts of oleic acid. Because each animal species stores fat with its own characteristic array of fatty acids, McGovern’s team was able to suggest the animal source. The stew was probably prepared with lamb or goat, since these meats con- tain about the same relative amounts of palmitic, stearic, and oleic acids found in the residues. 4ChemMatters, DECEMBER 2001 www.acs.org/education/curriculum/chemmatt.html Other components of the food Mixture residue suggested the remaining stew ingredients to be lentils, wine, and olive oil, seasoned with fennel or ere are two of the analytical methods used by chemists at the Museum of Archaeol- Hogy and Anthropology at the University of Pennsylvania to separate and identify the anise and other spices. “We have Sample remains of the feast. direct chemical evidence for some of Liquid chromatography (LC) is used to separate a mixture into its components. The the spices,” says McGovern. “We sample mixture is dissolved in a liquid and placed in a tube filled with a compound that is found compounds that come from chemically bonded so that it cannot move. This compound is called the stationary phase. fennel and others from some sort of The liquid contained in the sample, called the mobile phase, is then passed through the tube. peppery substance. We could deduce The components of the sample mixture spend part of the time dissolved in the liquid phase other spices from ancient texts and Separating and part of the time absorbed on the stationary phase. The components separate from each material from archaeological evidence of other by the relative times they spend with each phase. Compounds that spend less time plants that were available in the area attached to the stationary phase and more time dissolved in the mobile phase come out of at that time.” the column first. They were even able to suggest Gas chromatography (GC) is another technique for separating a mixture into compo- the meat cooking method used by nents. This time, the mobile phase is a stream of gas, often helium or hydrogen. The sample

is heated until its components vaporize. Then it is injected into the column. The sample is ILLUSTRATIONS BY CESAR CAMINERO these ancient chefs. When meat is Glass wool separated into components, based Column furnace cooked over a fire, chemical changes Carrier gas on the relative times they spend outlet occur near the surface of the meat, Sample with the mobile and with the sta- application Detector creating hydrocarbon compounds tionary phase. Separation column called polycyclic aromatic hydrocar- As the compounds emerge Manometer bons along with some sharp-tasting from the gas chromatograph, they compounds called cresols. Because enter another piece of equipment these chemicals were present in the called a detector. Here the behavior Integrator feast leftovers, the researchers con- of unknown compounds is com- cluded that the meat was first grilled pared to that of known com-

Synthetic air H N over a fire before the other ingredients Liquid pounds. In this way, the identity of 2 2 chromatography the unknowns can be established. Gas supply Recorder and seasonings were added. Power supply Gas chromatography Even if we don’t know exactly what went into the stew, we are pretty sure how the mourners washed it malt used to make beer. The third part of the plete, the museum sold tickets to a modern down. Many drinking bowls and serving jugs beverage was probably mead, because the feast in honor of King Midas. found were coated with a black film, all that remaining solids contained long hydrocarbon According to McGovern, researching the remained of an ancient beverage. When waxes characteristic of the kind that bees use meal was more than just a good excuse for a McGovern analyzed this residue, he concluded to make combs. Whenever honey is extracted party. It also provided valuable archaeological that it was a mixture of grape wine, barley from combs, some of the wax goes with it. information. The composition of the wine-beer- beer, and an alcoholic beverage made from mead beverage is similar to other beverages fermented honey called mead. The analysis, Restaging the known to have been consumed in ancient like that of the food, focused Europe, thereby supporting the idea that the OH ancient feast on finding specific compounds ancestors of the Phrygians were European. | Once the contents of that ancient feast — characteristic of the natural Also, the olive oil in the stew shows that the C—O were known with some confidence, the | ingredients used to make the Phrygians traded with people from other areas. researchers decided to have some fun and go HO—CH drink. “We know that the olive oil was imported,” one step further. With the help of the | The components of the says McGovern. “There are no olives on the museum’s caterer, they developed a recipe for HC—OH mix that told the story were central Anatolian plateau today, and there is no | the meal based on their chemical analyses and tartaric acid, calcium oxalate, evidence that olives ever grew there.” C—O— on their knowledge of other foods available in and beeswax. Tartaric acid Just think. The stuff in the back of your | the region at that time. Several brewers worked OH (see Figure 1), found in high refrigerator might be the research challenge on making a drink using methods that would concentrations in Middle East- just waiting for archaeologists of the future! have been used by ancient brewers. Tartaric acid ern grapes, indi- Figure 2 The winning concoction, named “King Figure 1 cated the presence Steve Miller is a science writer based in State OO– College, PA. His most recent ChemMatters article of wine. The second compound, Midas’s Touch” contained Muscat grapes, thyme honey, and barley fer- was “Spectroscopy—Sensing the Unseen” in the calcium oxalate (see Figure 2) is C September 2001 NASA special edition. mented together and colored bright also known as “beerstone” +2 Ca reddish-yellow with saffron. REFERENCES because it precipitates on the sides The Funerary Feast of King Midas. Posted by of beer fermentation and drinking C When the planning was com- the University of Pennsylvania Archaeology vessels. Because there was also and Anthropology Museum. www.museum.upenn.edu/Midas/intro.html – evidence of sprouted barley in the OO (accessed Sept 2001). area, researchers concluded the Gorman, J. King Midas’ Modern Mourners. calcium oxalate came from barley Calcium oxalate Science News, Nov 4, 2000, pp 296Ð298. ChemMatters, DECEMBER 2001 5 TTrollingrolling thetheSeasSeasforfor NewNew MedicinesMedicines By Harvey Black

he word “ocean” calls to mind pleasant chemists to examine, the pace of drug discov- growth of neighboring organisms. Coral reefs summer thoughts of sand and waves, ery seems to be slowing. At the same time, are home to many varieties of sessile organ- T gulls and boardwalks, and sailboats interest in ocean research is growing, includ- isms—organisms that latch onto the surface and surfboards. From our beach blanket per- ing oceanography, marine chemistry, and and wait for currents to serve up a steady spective, it’s hard to imagine that we’re marine biology. All of these fields are uncover- menu of passing prey. As you can imagine, a squinting out at a vast body of water covering ing sources of promising new materials. crowded sessile neighborhood means food 70% of the earth’s surface and housing 80% “The ocean is a resource of significant shortages. The most successful of these of all living things. When biologists and magnitude for the discovery of new pharma- organisms excrete secondary metabolites that chemists look at the ocean, they see even ceuticals,” says William Fenical, director of the slow the growth and reproduction of their more. To them, the ocean is a treasure chest Center for Marine Biotechnology and Biomedi- neighbors. of chemical compounds, waiting to be tested cine at the Scripps Institution of Oceanography Drug researchers look for interesting sec- for their possible effectiveness as healing in San Diego, CA. “After all, the majority of our ondary metabolites like these. After all, the medicines. planet is covered with water. The organisms in main problem presented by cancer cells is Over the centuries, humans have turned it present a breathtaking range of biological their rapid growth and reproduction. Would a to nature for healing. Plants, animals, and the diversity, and where you have biological diver- chemical produced by one of these sessile but chemicals extracted from them supplied our sity, you have chemical diversity. The range of territorial creatures prove useful in slowing the ancestors with the traditional means for curing natural products that are contained in sea life growth of tumor cells? diseases and managing their symptoms. Often is enormous.” Bugula neritina is a slimy, brown creature discovered by chance and tested by trial and belonging to a group of animals called bryo- error, these natural remedies were passed Searching for the zoans. Often mistaken for clumps of seaweed, from generation to generation in every culture. bugula colonies may be found clinging to boat By the late 19th century, scientists began right metabolite hulls and fouling water pipes—in short, nui- to analyze the active components and chemical Of particular interest to researchers is a sances all around. But that was before they compositions of these natural medicines. They category of chemicals called secondary were found to secrete a growth-inhibiting sub- saw obvious advantages in finding ways to metabolites. These natural products represent stance called bryostatin-1, a new tumor-slow- produce the most effective ones in large quan- a diverse group of chemicals that, while impor- ing cancer drug currently testing well in tities. In recent years, drug researchers have tant, are not produced or consumed at levels clinical trials. even learned how to identify and synthesize matching other products of an organism’s When Robert Jacobs of the University of new drugs in controlled laboratory settings. metabolism. Instead, secondary metabolites California–Santa Barbara, examines chemicals, Despite the incredible progress in modern do useful things like protect a plant from attack he says it’s like looking back through time. He drug synthesis, many important medicines by an insect—kind of a do-it-yourself bug is referring to the fact that humans, like all come to us essentially “as-is” from nature. The spray. Or they may serve to attract a member other terrestrials, trace their lineage to marine heart drug digitalis still comes from a plant of the opposite sex—a do-it-yourself perfume. organisms that came ashore long ago. “In called foxglove, and taxol, a cancer-fighting If you have ever had an unpleasant encounter many ways, the organisms in the ocean repre- drug, comes from the Pacific yew. with a skunk, you experienced the effect of one sent living fossils in terms of biochemistry.

BACKGROUND PHOTO FROM COREL PHOTODISC Although there are probably thousands of particularly effective secondary metabolite! You can sit and dream of making a molecule, desert and forest species left for drug Some secondary metabolites affect the but here are the templates for something that

6ChemMatters, DECEMBER 2001 www.acs.org/education/curriculum/chemmatt.html really works. These organisms—some of them “We have to be able to produce a lot of it. precede the first plants on earth by half a bil- If it’s a terrestrial plant, we might be able to lion years!” farm it. With marine sponges that grow at Produced by certain marine algae as a 3000 feet, we’re certainly finding aquaculture secondary metabolite, 5-hydroxy indole acetic very challenging. These things normally live acid stimulates growth. But slightly modified, it where there’s no light and it’s 5 °C. They don’t reduces swelling caused by arthritis, a painful want to live up on the surface,” Wright says. and often crippling disease. Similarly, salicy- Trying to culture organisms collected at

lates, the key ingredients in aspirin, are found PHOTO COURTESY OF DR. YUUJI TSUKII, HOSEI UNIVERSITY, TOKYO that depth poses a significant set of chal- in all photosynthetic plants as growth stimu- Tetrahymena is a one-celled marine protozoan lenges. The sea is very different from the land that finds its food by following the chemical lants. In humans, these salicylates are anti- signals emitted by dead or dying animals. Here, it in that meeting the needs of marine organisms inflammatory. is shown magnified 1000 times. demands whole new fields of specialization. Presently, scientists agree that they know how Whether a drug molecule will interact Looking for patterns to grow only about 1% of the collected marine with human tissues at all depends on some microorganisms in artificial environments. When discoveries begin to fall into pat- chemical architecture. There are molecular Their determination to increase that number terns, they suggest strategies in the search for receptors on the surfaces of human cells only underscores the vast trove of potentially new drugs. For example, if algae can produce whose jobs are to recognize and accept mole- beneficial chemicals just waiting to be tapped. a growth-stimulating chemical, researchers cules for further interaction with the cell. For a The sea, the ultimate source of every vari- want to test this compound to see if it has anti- drug molecule to be effective, or biologically ety of life, may hold the means for healing and inflammatory properties. active, it must pass this initial test. A passing enhancing that life. What life-saving chemical Drug researchers are looking closely at grade depends on very specific details of its treasures await our discovery? The potential the behavior of even the smallest organisms, chemistry. It must contain the “right” func- for discovering new medicines seems as vast hoping to discover interesting chemicals for tional groups, such as the OH (hydroxyl) as the ocean itself. testing. Tetrahymena is a one-celled marine group, in the “right” places. protozoan that finds its food by following the As there is no sure way to determine PHOTO COURSTEY OF AMY WRIGHT, HARBOR BRANCH OCEANOGRAPHIC INSTITUTE., INC. chemical signals emitted by dead or dying ani- whether a given molecule has all of the right mals. In a similar way, when you suffer a cut functional groups in the right locations, finding or other wound, your body sends signals from useful drugs often demands the testing of the wound to your bone marrow, which thousands of compounds. Sometimes, drug responds by sending cells to cleanse the researchers learn to recognize structural pat- wound. These cells find their way to the wound terns, which thereby narrows the search. Com- by following a path of fatty acids released from puter modeling may even suggest blueprints injured tissues. Scientists think that under- for synthesizing molecules based on the suc- standing how tetrahymena follows chemical cess of tests with similar biologically active signals might be useful in better understand- compounds. ing the process in humans. They want to learn what gene or genes in the tetrahymena is trig- Finding and farming gered and whether those genes direct the for- marine specimens Amy Wright of the Harbor Branch Oceanographic mation of any potentially useful chemicals. Institute is shown here in the foreground Drug researchers are fascinated by find- Collecting and analyzing specimens is the collecting samples for biomedical research. ing chemicals that serve one function in a work of marine chemist Amy Wright at the primitive organism and a different but possibly Harbor Branch Oceanographic Institute in Fort related one in humans. The challenge is to Pierce, FL. “In our freezer, we have about Harvey Black is a freelance science writer living in 26,000 different specimens. Although many Madison, WI. His article “Green Refrigerants” capitalize on that initial function and use it to appeared in the February 2000 issue of are from the same species, they still may be

PHOTO BY MIKE CIESIELSKI help people. ChemMatters. different from each other. You can have differ- ent chemistry depending on where you collect REFERENCES them.” Using modern-day submersibles, some Jacobs, R. Marine Pharmacology Research Program. University of California-Santa researchers collect organisms from as deep as Barbara Web site. 3000 feet. http://lifesci.ucsb.edu/EEMB/faculty/jac Collecting plants and animals and isolat- obs/research.html (accessed Sept 2001). Harbor Branch Oceanographic Institute Home ing potentially useful drugs are only the first Page. http://www.hboi.edu (accessed steps in finding new drug compounds. After Sept 2001). that, the real challenges begin. Despite the Ireland, C. Biomedical Potential of Marine almost limitless number of marine compounds Natural Products in Marine Biotechnology. In Pharmaceutical and Bioactive Natural waiting to be tested, turning even a fraction Products; D. Attaway and O. Zaborsky, of them into useful drugs is a long and Eds.; Plenum Press: New York, 1992; expensive process. vol.1.

ChemMatters, DECEMBER 2001 7 ChemSumer

By Doris R. Kimbrough

“Can someone please tell me what is the deal with B.O.? tions. In order for our noses to pick up Doesn’t make any sense. Do something good—hard work, a scent, a substance must first evapo- exercise—smell very bad. This is the way the human being is rate; you can’t smell something unless designed. You move, you stink. Why don’t our bodies help it travels through the air. Once the mol- us? Why can’t sweat smell good? Be a different world, ecules arrive in the nose, they must wouldn’t it? Instead of putting your laundry in the hamper, bind to our scent receptors to be you’d put it in a vase. Go down to the drugstore, pick up detected. Thousands of human scent some odorant and perspirant. You’d have a dirty sweat sock receptors, deep within the nose, cover hanging from the rearview mirror of your car.” an area the size of a postage stamp. —Jerry Seinfeld Furthermore, we humans detect and discriminate a fairly complicated, yet e all agree that air pollu- Dealing with personal air pollution fairly dilute array of molecules. When tion can be a serious is a multimillion-dollar industry market- you correctly identify the smell of a W problem, but what about ing deodorants, antiperspirants, mouth- strawberry, you have sorted through the kind of air pollution that is not washes, and breath mints to consumers about 300 different components at a related to car emissions or industrial who don’t want to stink, while selling concentration of 10 parts per million. smokestacks? We’re talking about per- fragrances, perfumes, and air freshen- That’s pretty sensitive, although still not sonal air pollution—pollution that ers to those of us who just want to in the same league with real experts like makes you wrinkle your nose in disgust smell better. dogs and many other mammals. Blood- when guys don’t bother to shower after hounds, for example, have 40 times as gym class. It’s the pollution that makes Your nose is many scent receptors as humans. you sit as faaaaar as possible from that an excellent The binding of a molecule to a girl in your English class who wears chemical detector scent receptor involves a highly specific half a bottle of perfume to school. And chemical reaction that is not at all well it’s the pollution that leaves no doubt What causes something to have a understood. Scientists do know that about who likes onions and who likes scent? Your sense of smell involves each of the approximately 10,000,000 some very interesting chemical interac- ILLUSTRATION BY DAN SHERBO extra garlic on their pizza. receptors in your nose responds to

8ChemMatters, DECEMBER 2001 www.acs.org/education/curriculum/chemmatt.html Why are some smells pleasant and others extremely disagreeable? There are a lot of hypotheses but not much in the way of experi- mental evidence. What is known is that some odors are universally disagreeable to all humans (skunks, rotten food, decaying ani- mals, or fecal odors), whereas others are objectionable only to some (cigar or pipe smoke, certain spices, or the perfume worn by that girl in your English class). It’s likely that our hate of certain smells is even a survival advantage. Avoiding rotten food and decaying PHOTO COURTESY OF MICHAEL TINNESAND Eccrine sweat glands are especially concentrated animals automatically makes you a healthier on the hands and feet. They produce evaporative person who will live longer! sweat to cool our bodies. PHOTO BY MIKE CIESIELSKI more than one different molecule and that the Let’s talk armpits! same molecule can trigger more than one Face it. Humans, as well as most of our receptor. Concentration and proportion are primate relatives, are a pretty stinky bunch. both important. A substance that smells agree- Relying on our perspiration to regulate our There are so many different chemicals able when dilute may be unappealing in higher body temperature, we make our skin and present in our odiferous axillary vaults (stinky concentrations, and a particular mix of sub- clothes a warm and moist breeding ground for pits) and fuming pedicurial regions (smelly stances can have a very different odor if the all kinds of bacteria. And those bacteria metab- feet) that chemists have still not identified all proportions of those chemicals are changed. olize the odorless chemicals naturally found in of them. The smelliest are butanedione, isova- What about the connection between smell our perspiration into smellier varieties. The leric acid, 4-ethyloctanoic acid, 5-androst-16- and memory? How often have you caught a armpit—or the axillary vault, if you prefer—is en-3-one, and 5-androst-16-en-3-ol. scent of something, good or bad, and the source of odors that most modern humans Butanedione smells “cheese-like”, and isova- exclaimed, “Oh man! What’s that smell? It find offensive. leric acid has a sweaty odor (big surprise reminds me of . . .” Smells can evoke strong Humans have two types of sweat glands: there!). The smells of the last two have been memories because when molecules bind to apocrine and eccrine. Eccrine glands are found described as resembling stale urine and goats, your scent receptors, the resulting nerve sig- all over the body, including the armpits, but respectively. Aren’t you glad we didn’t include nals travel to the limbic system, the primitive especially in the hands and feet. They are stim- a scratch ‘n sniff strip? part of the brain responsible for emotions and ulated by heat to produce the evaporative sweat Now that we know why we smell, how do memory. Here, scents and memories are inti- that cools us down when we are baking in the we keep from offending people? Today’s con- mately linked (see Figure 1). sun or exercising vigorously. But they also sumer already knows the answer to that ques- respond to emotional tion: soap, deodorant, and antiperspirant! stress, like that sink- Soaps do a double duty by washing away ing feeling you get offensive chemicals as well as killing the when you forgot to do microbes responsible for turning them into Olfactory bulb of the brain your homework. smelly substances. But, as you well know, Apocrine glands soap provides only a short-term solution. are located in the There are always more microbes where those armpits and pubic came from, always ready to produce more area and are also stench. Washing with deodorant soaps pro- Bone stimulated by emotion vides a slightly more lasting effect since they and stress. The odors kill more bacteria. characteristic of armpits AlCl3•6H2O + H2O ➞ Alx(OH)y•nH2O + other salts are due to Aluminum Insoluble hydroxide gel apocrine chlorohydrate Olfactory sense cell secretion. Apocrine fluid is rich Is there a difference between a deodorant in organic substances, and an antiperspirant? Maybe not in terms of odorless when fresh smell, but there is a big difference in their PHOTO BY MIKE CIESIELSKI. ILLUSTRATION MARIE DAUENHEIMER but irresistible to bac- chemistry! Deodorants kill the bacteria that Molecules teria, which quickly produce the stink. And they usually contain convert them into other, more appealing odors to mask the Figure 1. Our noses are sensitive to molecules of evaporated substances that new chemicals with stimulate tiny hairs of olfactory sense cells. Resulting nerve signals travel offensive ones (see the discussion on per- rapidly to the brain. characteristic stench. fumes on the next page). Antiperspirants, on

ChemMatters, DECEMBER 2001 9 the other hand, do a double duty of killing Scents sense stitutes are often used in modern perfumes. bacteria while constricting and blocking your Deodorants and antiperspirants were not Sometimes, the synthetic version of an essen- sweat glands. Most antiperspirants contain readily available until the 20th century. And tial oil exactly duplicates the molecular formula aluminum and/or zirconium salts, which form before indoor plumbing became widely avail- of its natural source. But other perfumes con- an insoluble hydroxide gel for blocking sweat able in the late 1800s, bathing was a compli- tain synthetic ingredients that have no natural pores. cated process. Think about it. You couldn’t just counterpart—they just smell good. The metal salts also act as astringents, hop in the shower. You had to heat water on a Perfume artists—actually chemists— substances that shrink pores, allowing less stove, haul it to the tub, fill the tub, and then make perfume by mixing different essential perspiration to flow. Actually salts of most of haul it away when you were done. Indeed, until oils. Examples of some chemicals the metals in the periodic table would work this century, frequent bathing was that are contained in essential well as antiperspirants. Unfortunately, many viewed by many people as oils can be found among the would be so toxic that there would be few cus- unhealthy. Given the effort “good”-smelling molecules on tomers coming back for more! involved, they may have page 11. The resulting combi- been right! nations are tested at different Dragon breath Just because baths temperatures and pHs to were less available didn’t make sure that the scent will There are two kinds of bad breath or hali- mean humans needed them not change in changing tosis, to be fancy: chronic and food-related. less! What was an odiferous conditions. You wouldn’t We’ll assume you don’t smoke cigarettes. If pre-Victorian person to do to want to walk out the door you do then your bad breath is your avoid offense? It’s no coinci- smelling great, only to own fault! Like other dence that the popularity of smell like a garbage can body scents and perfumes dates back upon entering a warm odors, to ancient Egypt. room! The perfume oil chronic For centuries humans have PHOTO BY PHOTODISC must be dissolved in a PHOTO BY MIKE CIESIELSKI bad been burning incense, smearing solvent—typically, an breath is themselves with scented oils, and ethanol–water mixture—at the correct concen- caused spraying on perfumes and colognes—all in an tration for perfume (20–30% essential oil), by—you effort to mask or eliminate unpleasant odors. cologne (8–15% essential oil) or aftershave guessed The art of perfumery is ancient and complex. (1–3% essential oil). it—bacteria. The base ingredient of any perfume is its In pre-Victorian times, perfumes masked Give them essential oil. Historically, the source of essen- the smells of unwashed humans, rotting secure moist tial oil or essence was plant material (such as garbage, and raw sewage. Perfumed handker- places to set flower petals, bark, fruits and their peels, nuts, chiefs and gloves were very popular, some- up shop, and and leaves), and occasionally animal material times pressed over the mouth and nose to they readily turn (such as musk, ambergris, and civet). This protect against the “bad air” blamed for dis- their organic-rich concentrate was derived in a variety of differ- ease. Today, our modern combination of surroundings into ent ways. Today, essences still come from cleanliness and effective medicines means that smelly byproducts. To cure and prevent this plant and animal materials, but synthetic sub- we can rely on fragrances for what they do kind of bad breath, you need to do all those best—smell good. things that the dentist nags you about— regular professional cleanings, flossing, Doris R. Kimbrough teaches chemistry at the brushing, and limiting sweets. But if you do University of Colorado–Denver. Her article “Noisy Knuckles and Henry’s Law” appeared in the all of these things and the bad odor per- December 2000 issue of ChemMatters. sists, then you should see your dentist. You might have an infection. REFERENCES What can we do about garlic and Atkins, P. W. Molecules, Scientific American Library: New York, 1987. onion breath? Not much, it turns out. Gomes, A. R. University of Toronto Web Onions and garlic owe their pungent page. Perfume Bottles: A Study of smells and tastes to sulfur-containing Contemporary Material Culture, A Short organic molecules, a stinky collection History of Perfume, www.chass.utoronto.ca/history/material shared by rotten eggs and skunks. Eat a _culture/gomes/per.html (accessed Sept. clove of raw garlic, and a set of these com- 2001). pounds ends up in your bloodstream to be Lehman, J. W. Operational Organic Chemistry, 2nd Ed., Allyn & Bacon: delivered to the rest of your body. In the Boston, 1988. lungs they freely cross over membranes to Merck Index, 12th Ed., Merck & Co.: Rahway,

enter your breath. Mouthwashes and PHOTO BY MIKE CIESIELSKI NJ, 1996. toothpastes may mask these smells, but Selinger, B., Chemistry in the Marketplace, only time will really get rid of them. 5th Ed., Harcourt Brace: Sydney, 1998.

10 ChemMatters, DECEMBER 2001 O O || || CH3——C—C——CH3 Strong cheese smell Butanedione

O CH2—CHCH2—SS—CH2CH2CH3 || Onion CH3—CH—CH2—C—OH Rancid sweaty smell Allyl propyl disulfide | Isovaleric acid CH3

O || CH3—CH2—CH2—CH—CH2—CH2—C—OH | CH2—CH3

CH3 Goats 4-ethyloctanoic acid CH3——N Rotten Fish H2S Rotten Eggs Trimethylamine Hydrogen sulfide CH3

CH3 | Skunk CH3—CH—CH2—CH2—SH 3-methylbutane-1-thiol

ChemMatters, DECEMBER 2001 11 MysteryMatters

Luminol—Casting a Revealing Light on Crime

By Tim Graham n a summer morning in July 1992, Chris Campano phoned Oklahoma City police to Oreport that his wife Karen was missing. Fol- lowing their quarrel, she had not returned home on the previous evening. She had not shown up at work the following morning. Upon interviewing Chris, police luminol dissolved in a buffer with hydrogen peroxide or reported that nothing appeared unusual at the Cam- sodium perborate. Sometimes, a thickening agent may be pano home, but they asked permission to search the added to reduce the running of fresh stain.” house after Chris mentioned that the house had been Dr. Rowe cautions that the suspected stain must be burglarized just a few days before Karen’s disappear- sprayed repeatedly since the luminol chemiluminescence ance. fades quickly. “The spraying is done in total darkness and Chris Campano’s story was inconsistent, and he the chemiluminescence is recorded with a tripod-mounted soon emerged as the primary suspect. Police suspected camera set for time exposure. High-speed black and white that an argument between Chris and Karen over Chris’s film is used.” drug use had escalated into a violent encounter. Okla- Luminol is a chemical substance that will luminesce homa City police soon found evidence that indicated (give off light without any heat, ”cold light”) when it is oxi- that if a murder had taken place, it probably had dized. Substances that tend to give off light as the result of occurred within the house. a chemical reaction of this sort are said to be chemilumi- Police found a large stain on the bedroom carpet nescent. You are probably familiar with a chemical light that was still wet and appeared to be blood. Investiga- stick or necklace that you might purchase at a concert or at tors soon concluded that a violent murder had taken the circus. The outer plastic container holds one chemical place and that the victim was most probably Karen reactant while an inner glass container holds the second Campano. Investigators returned to the residence at reactant, hydrogen peroxide. Bending the plastic breaks night to conduct more tests, this time using the chemi- the inner glass ampule, and the chemicals react and give cal 3-aminophthalhydrazide, commonly known as lumi- off light . . . often for several hours. (See “Chemilumines- nol. cence, the Cold Light” by Gail Marsella in the October Apart from the bloodstained carpet, the house 1995 issue of ChemMatters.) Many living organisms such appeared normal to the naked eye. But when investiga- as a firefly also have the ability to create light by means of tors sprayed the bedroom with luminol and turned out a similar chemical reaction. This type of chemilumines- the lights, the room glowed with an eerie blue color, cence is called bioluminescence. casting light on a gruesome and brutal crime. All chemiluminescent systems work basically the Dr. Walter Rowe, who teaches forensic science at same way. Although many reactions that you might be George Washington University in Washington, DC, familiar with tend to release energy in the form of heat, describes the process as being pretty simple. “The some chemical reactions emit light instead. For a chemi- luminol reagent is mixed up and sprayed on the sus- cal reaction to produce light, it must first produce a mole- pected stain, using an atomizer. The reagent consists of cule or ion in a high-energy or electronically excited state.

12 ChemMatters, DECEMBER 2001 www.acs.org/education/curriculum/chemmatt.html The excited molecule has at least one electron It’s interesting that during the O.J. Simp- through the air. The blue glow continued, trac- in a higher-energy orbital than would normally son trial for the murder of Nicole Simpson- ing a pathway from the bedroom, through the be found if it were in its lower-energy ground Brown, Simpson’s defense attorneys kitchen, into a utility room, and outside down state condition. But as the electron loses challenged the luminol results on stains found the back steps. It continued into the driveway energy, it falls from its excited state back to in O.J’s Ford Bronco with the remark that the where the trail abruptly stopped. ground state, and emits energy in the form of dried substance could just as well have been Forensic investigators had ample evi- light (see Figure 1). taco sauce. They argued that oxidases from dence to suggest that a violent murder had In fact, any source of light—whether the onion in the taco sauce could have occurred and that the body, presumably that of luminescent or incandescent (the glow emitted resulted in a false positive. In forensic terms, Karen Campano, was dragged through the by a very hot object)—can be traced back to the luminol test is called a presumptive test, house and out into the driveway where it was the absorption of energy and its release as meaning that positive results suggest without probably placed in the trunk of a car and car- light. To understand the process of absorbing proving the presence of blood. Other tests are ried away for disposal. More tests completed energy and emitting light, imagine an electron necessary before the presence of blood is the story. A species-determining test called the on a roller coaster ride. Ordinarily, the electron confirmed. Ouchterlony test determined that the blood is on the ground. When it gets on the ride, energy pushes O O it up. The electron Oxidant C C

can only go as high PHOTO BY MIKE CIESIELSKI NH (like H2O2) O– + Light as the tallest hill of NH Base and O– the roller coaster C catalyst C and no farther. But NH2 O (like iron in NH2 O hemoglobin) it’s not very stable Luminol Aminophthalate ion up there! The elec- (3-aminophthalhydrazide) tron soon heads Figure 1 back to its lower energy ground was human. Finally, a DNA analysis state, emitting its confirmed the blood to be that of Karen own version of a Campano. scream—light! Luminol undergoes chemiluminescence in the The use of luminol directed inves- presence of an oxidizing agent like hydrogen Here’s how lumi- peroxide, a base like sodium hydroxide tigators to the presumptive evidence nol reveals a blood- (NaOH), and a catalyst. Various metallic ions from which they were able to piece stain. The iron- will catalyze the reaction. Iron found in the together the events of that fateful night hemoglobin molecules of red blood cells is containing heme pro- particularly effective. The resulting in July 1992. Just as Chris Campano’s tein in the blood sam- aminophthalate ion is first produced in an murder trial began, the remains of ple acts to decompose electronically excited state. As electrons return Karen’s body were discovered in a to the lower-energy ground state, energy is the hydrogen peroxide emitted as light. remote area. Dental records and DNA component of the lumi- analysis of the bone marrow confirmed nol reagent. When this happens, the luminol is the identification. The skull showed oxidized to form a product with electrons in a When crime scene investigators sprayed upward of 15 fractures that could only be the high-energy state. As these electrons return to the darkened Campano bedroom with luminol, result of the blunt force trauma experienced their lower energy ground state, the visible the room glowed with so much light that they during a severe beating. result is a bluish light. could easily see each other! With dramatic With the overwhelming evidence against But a positive luminol test doesn’t prove positive test results, luminol remains the pre- him, Chris Campano confessed to the murder that the sample is blood. In fact, many other ferred presumptive field test for blood. It easily and in January 1994 was found guilty of substances, both inorganic and organic, can reveals even the smallest traces, even if the manslaughter and sentenced to 1000 years in set luminol aglow. Substances of animal origin crime scene has been scoured and cleaned to prison with no possibility of parole. such as pus, saliva, brain tissue, and bone remove all visible evi- marrow, as well as inorganic chemical oxi- dence. Tim Graham teaches chemistry at Roosevelt High School in Wyandotte, MI. His dants like copper, potassium ferricyanide, In the Campano most recent article “Light-Emitting Diodes—Tune in to the Blues” appeared in potassium permanganate, potassium dichro- house, luminol told a the April 2001 issue of ChemMatters. mate, nickel and cobalt nitrates, rust, and grim tale. Besides react- REFERENCES iodine can all initiate the luminol reaction, thus ing with the blood spat- DuPre, A. Blood or Taco Sauce? J. Chem. Ed. 1996, 73 (1). giving false postives. Even vegatable oxi- ters on the walls, Koblinsky, S. Human Blood Identification: A Forensic Approach. dases—enzymes found in apples, apricots, ceiling, and window cur- J Chem. Ed. 1984, 61 (6). beans, horseradish, potatoes, turnips, cab- tains in the bedroom, it Nimitz, J. S. Experiments in Organic Chemistry, Prentice-Hall: bage, and onion—can start the decomposition illuminated cast-off Englewood Cliffs, NJ, 1991. The Chemical Detective Forensic Science Web site. The Luminol Test. of hydrogen peroxide, leading to false positive trails probably tossed www.deakin.edu.au/forensic/Chemical%20Detective/ results. by an object swung Luminol_test.htm (accessed Sept 2001).

ChemMatters, DECEMBER 2001 13 By Peter Banks

On May 10, 1996, a sudden fierce storm his companion for dead. Miraculously, how- you risk losing a significant amount of body trapped several climbers high on Mt. Everest ever, he managed to rouse himself and walk heat from your head alone. just as they were starting their descent from down to the next camp. From there, he was You run for the bus and arrive in a sweat. the summit. In what became the deadliest taken off the mountain by helicopter—though Now you’re losing heat through evaporation. single climbing tragedy in the mountain’s eventually losing both hands and his nose as a Sweating is another one of the body’s ways of history, a total of eight people perished. One result of frostbite. cooling down. When water changes from a liq- who managed to survive was a Texas Weathers’s ordeal tells us two things uid to a gas, it absorbs heat called the “latent climber named Beck Weathers. about hypothermia. It is a ferocious killer, and heat of vaporization.” That’s welcome on a hot the human body uses extraordinary means to summer day when the evaporation of sweat lthough television can reduce the combat it. Humans are among the warm- keeps you cool. But if your skin or clothing effort to survive in the wilderness to blooded or endothermic animals that generate gets damp with sweat on a cold day, the result A a few hours of entertainment and a heat from the metabolism of food and then can be an unwanted heat loss. chance to win a million dollars, in reality—a maintain fairly constant body temperatures by Running also cools you by convection, reality far from “reality TV”—wilderness sur- using a variety of strategies. In humans, the the phenomenon behind wind-chill charts. vival can be a struggle for life, and the chal- complex biochemistry that is taking place in When you are standing still and the air is still, lenge of survival in the wilderness has claimed our bodies requires an internal temperature of your body soon warms a thin layer of air next

PHOTO BY MIKE CIESIELSKI the lives of many soldiers, explorers, and 98.6 °F (37 °C). Straying in either direction to its surface, creating a warm, surrounding adventurers. And in the cold winter months, from that mark for an extended period of time shell. But if you are running or the wind is one of the deadliest aspects of the struggle is means trouble. blowing, the air passing over you strips off this exposure to numbing cold and its result, warmer layer, leaving you vulnerable to radia- hypothermia. Losing heat tive heat loss. As Weathers tells it in his recent book, To think about all the ways the human Finally, you make it to the bus stop and Left for Dead: My Journey Home from Everest, body can lose heat, picture a cold fall morning. sit down on a bench to catch your breath. a search party found You leave the house without a jacket or hat. Here, another kind of heat loss becomes a fac- him and another The minute you step outside, you begin to lose tor. Conduction is the direct transfer of heat climber close to heat from exposed parts of your body by radia- from one object to another. Press the bare skin death in the snow. tion, the emission of infrared energy. But not of your arms against a cold concrete or wood Calculating that a all parts of your body are affected in the same bench, and you’ll feel how conduction drains rescue was too late way. Blood, which is largely water, has a high more heat from your body. to save Weathers’s heat capacity and serves to distribute heat The effects of radiation, evaporation, con- life and would jeop- energy to all parts of the body. Parts of the vection, and conduction often combine to ardize those trying body with large blood supplies—your head, cause heat loss. You can think about how to save him, the res- for example—are locations where maximum some or all of them affect this example: The air cuers left him and heat loss can occur by radiation. Without a hat, you inhale is warmed and humidified before it

14 ChemMatters, DECEMBER 2001 www.acs.org/education/curriculum/chemmatt.html reaches your lungs. But every time you exhale stayed warm enough for this warm, moist air, you are losing heat. him to stagger down the Preventing hypothermia involves both mountain in a raging conscious and instinctive behavior. Common storm. sense tells you to put on a sweater and seek As serious as is njoy the crisp cold winter months! Here shelter when you’re feeling cold. You can also the chronic cold feared is your hypothermia defense guide. move around, swing your arms, and jump in by mountaineers and place, actions that cause the skeletal muscles polar explorers, Stay dry. Dampness reduces the insulation of many to produce heat. hypothermia is more clothing materials, and the evaporation of water on your But your body has a few warm-up acute and immediate if body or clothing draws heat. If your clothes become wet, strategies that require no conscious effort. one were to fall acci- change into something dry. If that’s not possible, then cover Muscles generate heat through shivering. dentally into cold water. yourself with a nonbreathable material like a plastic rain suit Shivering is the involuntary contraction and Completely immersed, to prevent evaporation. relaxation of skeletal muscles to generate the body cools rapidly Don’t get sweaty. Because dampness cools you down, avoid getting PHOTO BY PHOTODISC heat rather than work. as water, with its And “goose greater capacity for sweaty if you are hiking, skating, or bumps”? Here’s heat, rapidly drains cross-country skiing on a cold day. where it gets away the heat energy Instead, open your jacket, take off your funny. Humans, like from any submerged gloves, or take off your hat to prevent other mammals, objects. Who can forget overheating. Put them on again when come with a cover- the scene in the movie you stop exercising. ing of hair. One Titanic, in which pas- If you are tired, rest way a mammal sengers jumped into and eat. Your body cannot fight reacts to heat loss sea wearing life vests hypothermia when you’re exhausted is by contracting only to become victims or out of food. Shivering is the contraction and relax-

the tiny muscles at of the icy water? ation of your muscles, and it takes energy. PHOTO BY MIKE CIESIELSKI the base of each Don’t eat snow for water. It takes heat to melt snow. If you’re already hypothermic, you cannot afford hair, thus creating a fluffy A small layer of insulation in which air pockets retain the heat required to bring the snow to body temperature and body heat. In humans, our meager supply of survivor melt the ice crystals. If you need emergency water, melt the snow first and then drink liquid water. surface hair stands up to no avail. All we have Last winter, there If you fall into cold water, keep as to show for the effort is bumpy skin. were news accounts much of your body out of water as possible. Unable to create our own thermal layers, worldwide about a 13- Especially try to avoid submerging your head, from which we rely on clothing to do the job. We’ve month-old toddler, heat loss is greatest. learned that in the coldest climates, layers Erica Norby, from trapping the most air next to the skin work Edmonton, Canada, best. Fluffy woolens, down-filled quilted layers, who wandered from her and synthetic thermal weaves and knits all house into the frozen work well in freezing temperatures. –20 °F (–29 °C) night. When her mother found wilderness medicine, should be called to treat her, about two-and-a-half hours later, she was acute cases of hypothermia. But for most of Serious cold lying in the snow without a pulse, not breath- us, the best advice is to avoid hypothermia in Most of us will never experience anything ing, and her legs already purple. the first place. more than shivering or goose bumps as we One thing worked in Erica’s favor, react to the cold, but when severe hypothermia though. She was small. Young children have a threatens, the body marshalls more drastic larger surface area to body mass ratio than do defenses. For Beck Weathers and other “lucky” adults. When suddenly exposed to snow or icy Peter Banks is a science writer living in Fairfax, VA. survivors, the body gives up trying to keep its water, small bodies cool so rapidly that the His most recent ChemMatters article was “Fats— whole mass warm and instead just retains heat body’s organs are, in effect, flash frozen before Fitting Them Into a Healthy Diet” in the October 2000 issue. in the core zone, where the internal organs are. the brain and other organs incur permanent Normally, much of the heat in the core of your damage. Remarkably, Erica’s heart started body is eliminated when the warm blood flows beating again as she was rewarmed in the hos- REFERENCES from the internal organs to the blood vessels pital. Even more remarkably, her doctors Forgey, W. W. Basic Essentials: Hypothermia, Globe Pequot Press: Guilford, CT, 1999. in the cooler skin. Confronting chronic cold, reported that she suffered little, if any perma- Davenport, G. J. Wilderness Survival, these outer blood vessels narrow by a process nent injury. Stackpole Books: Guilford, CT, 1998. called vasoconstriction. Treatments for acute or chronic Krakauer, J. Into Thin Air: A Personal Account When rescuers found Weathers, his hypothermia involve applying heat—but care- of the Mount Everest Disaster, Anchor Books: New York, 1998. hands were frozen, the right one a third of the fully. When someone with deep hypothermia is Ice: Stories of Survival from Polar Exploration, way up his forearm. But despite this drastic warmed too rapidly, the heart can stop. Health Willis, C., Ed. Thunder’s Mouth cooling of his arms his legs, his body core care professionals, especially those trained in Press/Nation Books: New York, 1999.

ChemMatters, DECEMBER 2001 15 Chem.matters.links

Feasting a la 2 medium onions, chopped Add onions, celery, and gar- tom of the kettle. Add the King Midas 1 tablespoon honey lic to the same kettle. Cook and broth, rosemary, thyme, sliced 3/4 cup of chopped celery stir over medium heat until the carrots, cayenne (if desired), ithout modern conveniences W 2 garlic cloves, peeled and vegetables are soft and starting and browned meat. Cover the like stoves, ovens, and minced to turn brown. Reduce the heat kettle and place in the oven to microwaves, ancient chefs 3 tablespoons all purpose flour and add the honey and fennel simmer at 300 ¼F. labored over open fires to turn 1 cup water seed. Stir in the flour, and cook After 1.5 hours, check to see if out dishes fit for a king’s feast. 2 cups low-sodium beef broth until the flour is no longer the meat is tender and the veg- Using modern kitchen equip- 1/2 tsp each of ground cumin white, about 2 minutes. Slowly etables are no longer crisp. If ment and ingredients, a team of and fennel seed stir in the water, scraping up the stew is done, add the chick- Philadelphia chefs prepared a 1 tsp each of dried rosemary any browned bits from the bot- peas and put the dish back in banquet menu based on the and thyme (or 1 tablespoon the oven for 15 minutes. leftovers. You can find a few of each of chopped fresh) Taste carefully and add more their recipes at www.museum. 1/4 teaspoon cayenne pepper salt and pepper if necessary. upenn.edu/Midas/recipes. (more if you like it HOT!) Serve in shallow soup bowls html. 2 large carrots, peeled and garnished with sprigs of water- But what about the main sliced cress. Serve with pieces of pita dish? The roasted lamb stew 1 16-oz can of chickpeas bread drizzled with olive oil and appears on the Web page as a (garbanzo beans) drained honey. list of suggested ingredients. and rinsed ChemMatters knew you would Fresh watercress for garnish want to make a batch, so we concocted a recipe for you and Preheat oven to 300 ¼F. Place your friends to try. If it sounds lamb cubes in a large bowl and suspiciously like a recipe for sprinkle with salt, pepper and beef stew, you can probably cumin. Heat 2 tablespoons of guess our source of inspira- oil in a large heavy kettle over Carry the card! tion. medium-high heat. Add meat Go ahead. Be brave! And if ChemMatters gives extra credit in this and brown it on all sides, about you and your friends decide to issue by providing a handy chemistry ref- 5 minutes. Transfer the stage a feast of your own, tell erence card specially designed for you to browned meat to a plate, leav- us about it. Better yet, send put in your notebook. But first, let’s put it ing the hot fat in the kettle. pictures to to work on this challenge. [email protected]. Refer to the Functional Groups com- parative table. For each of the named King Midas’s groups, you’ll see a general formula, a structural Lamb Stew formula, a typical example of a compound with the functional group, and its condensed formula. 6 servings (But you know your friends better than we do.) Look through the articles in this issue of ChemMatters to find 2 pounds of lamb shoulder these examples: meat cut into 1-inch cubes, 1. A cheesy ketone visible fat removed 2. Two amines for the garbage dump salt 3. An aromatic aldehyde that is good on toast ground black pepper 4. The acid that sends you to the shower 2 tablespoons olive oil COURTESY OF UNIVERSITY OF PENNSYLVANIA MUSEUM OF 5. The acid found in wine and grape juice ARCHAELOGY AND ANTHROPOLOGY 6. An amine that can be set aglow

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