THAT’S THE WAY THE COOKIE CRUMBLES (17 page)

Picture a castle in Old England. Its dingy halls are lit by torches, and a fire struggles to warm the cold, damp air. Now give a thought to how the servant responsible for such things started that fire. It wasn’t easy. Carefully, he made a little pile of tinder, probably of wood shavings or linen threads. Then he struck a flint repeatedly against a piece of metal, hoping that the sparks he produced would ignite the flammable material. Today, we would just strike a match. Oh, how we take our modern conveniences for granted! Reliable matches, those little chemical-coated sticks that have had such an impact on history, are a recent invention. Let’s return, however, to our dimly lit seventeenth-century castle, the domain of King Charles II.

King Charles heard tell of a brilliant German entertainer who had a reputation for lighting up a room with his antics — literally. So he invited Daniel Kraft to amaze the royal court. And that he did. Kraft took a little bit of a soft, waxy substance from a bottle and placed it on a pile of gunpowder. Within a few seconds, as if by magic, the gunpowder burst into flame. Charles and his guests, including Robert Boyle, the famed “natural philosopher,�� had just witnessed a demonstration of the wondrous properties of phosphorus. (For more on this see p. 237.)

Kraft had learned the secret of concocting this amazing substance from the alchemist Hennig Brandt, who discovered it, in 1669, by allowing a vat of urine to boil dry. He had been trying to find the secret of life, which he thought was concealed in this bodily secretion. Boyle was captivated by the eerie glow of phosphorous and by its ability to burst into flame. But the only clue about its derivation that he could squeeze out of Kraft was that it came from “somewhat that belonged to the body of man.” One of Boyle’s apprentices remembered seeing a similar demonstration in Hamburg, and, at his master’s request, he tracked Brandt down and learned the secret. Boyle immediately began to experiment with phosphorus, and he even thought of making a luminous watch dial with it. But his most memorable experiment involved dipping a wooden splint in sulfur and then pulling it through a piece of paper to which he’d applied a little phosphorus. The friction generated heat, which ignited the phosphorus, which ignited the sulfur, which ignited the wood. The match was born.

Boyle’s match, however, turned out to be no more than a curiosity, because phosphorus was very hard to come by, and its ignition was hard to control. Johan Gahn of Sweden solved the availability problem when he discovered that bones are made of calcium phosphate and that by heating these in the presence of carbon he could isolate phosphorus. Soon, people could purchase little bottles coated on the inside with phosphorus. To produce a flame, one had to scrape a splint dipped in sulfur against the inside of the bottle and then rub it on a cork. Sometimes, though, all of the phosphorus, and the person who was scraping at it, would ignite. Peyla, an Italian chemist, got around this difficulty in an ingenious way. He sealed a candle with a piece of phosphorous attached to its wick inside a glass tube. He dipped the tube into hot water, melting the phosphorus, which then impregnated the wick. When he broke the glass, the phosphorus was exposed to oxygen, and the wick ignited. While these inventions were clever, a serendipitous discovery made in 1825 by an English pharmacist was to eclipse them all.

A customer had asked John Walker to make up a mixture of antimony sulfide, potassium chlorate, and vegetable gum because he had heard that this mix would ignite when struck. Walker did as requested, and he noted that a tear-shaped drop formed on his stirring rod. When he tried to scrape it off, it burst into flame. Walker began to make matches based on this method, but he never patented the process. Samuel Jones saw a demonstration of Walker’s invention and managed not only to capitalize on it but to improve on it as well. He added sulfur to the mix, making his “lucifers” easier to ignite — but at a cost. The user had to put up with the choking stench of sulfur dioxide produced by the burning sulfur.

Then, Charles Sauria of France had an idea. By adding a little easily ignitable phosphorus to the mix, he could reduce some of the offensive components. Soon, these newfangled lucifers flooded the market. They also caused hospitals to be flooded with miserable patients. White phosphorus is highly toxic, and people who made matches routinely developed “phossy jaw,” a terrible condition in which the jaw bone disintegrates. Then further experimentation yielded the discovery that white phosphorus, when heated in the absence of air, converts to red phosphorus. The red variety is not toxic, and it ignites at a much higher temperature. It didn’t take long for this observation to trigger the formulation of safety matches. Manufacturers would dip a splint in paraffin, then coat it with a mix of sulfur (a good fuel), potassium chlorate (to provide oxygen), and glue. One ignited the match by rubbing it on a strip of red phosphorus and ground glass (for friction) that was attached to the outside of the matchbox.

And so it was that by the end of the nineteenth century, the flint and the tinderbox were relegated to the dustbin of history. Matches had struck a chord with everyone. And, with the wide availability of safety matches, people no longer had to worry about one of their lucifers igniting in the cupboard when a rat gnawed on its tip. Not unless the rat knew how to remove a match from the box and strike it against the phosphorus-coated strip.

Like most chemists, I like to cook. After all, what is cooking but the appropriate mixing of chemicals? In the lab, we use flasks and beakers, but how do we equip our kitchens? At Tiffany’s in New York City, you can procure a silver frying pan for thousands of dollars; specialty stores sell gleaming copper pots for a couple of hundred, while you can buy a thin aluminum pot most anywhere for a few bucks. What’s the difference?

In a trembling voice, the gourmet cook will describe how hot spots on the bottom of a pan can destroy a delicate sauce. But we can avoid such tragic outcomes by choosing cookware that allows for efficient heat conduction and precise heat control. Silver is an ideal material for this, but it’s very expensive. Copper conducts heat almost as well, but it can dissolve in food and cause nausea, vomiting, and diarrhea. Copper cookware lined with tin or stainless steel is the solution; however, this lining eventually wears off and has to be replaced. Cookware manufacturers also make aluminum or steel pans with a thin layer of copper on the bottom, but such a small amount of copper does not improve the pan’s heat conduction.

Aluminum itself is an excellent conductor. In fact, more aluminum cookware is sold than any other type. But some cooks have discarded their aluminum pots and pans in response to reports linking aluminum with Alzheimer’s disease. Most researchers today do not believe that aluminum is a causative factor in Alzheimer’s, and, in any case, tossing out our aluminum cookware would have no effect. Most of it has a nonstick finish, but even people who use uncoated aluminum for both cooking and food storage ingest only about 3.5 milligrams of the metal every day. Compare this with the roughly twenty milligrams we consume daily as a natural component of food, or to the one thousand milligrams found in a daily dose of the antacid we take for an upset stomach. A single buffered pain reliever contains more than ten milligrams of aluminum.

If you want to put your mind completely at ease, then you should avoid cooking or storing highly acidic or salty foods — say, tomato sauce, rhubarb, or sauerkraut — in uncoated aluminum pots for long periods. In fact, a good general rule is to store food in the refrigerator in glass containers, not in pots or pans. Even though storing foods in metal containers poses no danger, aluminum pots will sometimes discolor as they react with food. To restore a discolored pot’s finish, try using it to simmer a couple of spoonfuls of cream of tartar dissolved in a quart of water for fifteen minutes.

A new kind of aluminum cookware, made of anodized aluminum, has recently arrived in the marketplace. It is usually gray-colored, it’s harder than stainless steel, and it conducts heat better; it’s also eternally nonstick, scratch resistant, and easy to clean. The process of anodizing involves passing the aluminum through a series of electrochemical baths, which cause a hard layer of aluminum oxide to form on the surface. This layer is nonreactive, and it does not leach aluminum into food.

The original nonstick coating was Teflon, discovered accidentally in 1938. This inert substance does not react with food in any fashion — words of comfort to anyone who has ever worried about swallowing the bits of Teflon coating that flake off older cookware. The perfluorocarbon resin passes through the body unchanged. Teflon may, however, release some toxic vapors if heated to high temperatures for long periods. While this represents little risk to humans, there have been isolated reports of pet birds being overcome by the fumes.

Just as Teflon cookware represents modern times, so cast iron cookware symbolizes traditional cooking. Cast iron is a good conductor of heat, and, since small amounts of it dissolve into food, it even serves as a dietary source of iron — one of the few nutrients in short supply in the North American diet. We should season our cast iron cookware to keep it from rusting and to prevent food from sticking to it. To do this, coat the pan with a thin layer of oil and then heat it. The oil will react with oxygen to form a tough, smooth, impervious layer.

Stainless steel is durable and does not tarnish. We make it by alloying iron with other metals, most notably nickel and chromium. Since stainless steel’s heat conduction tends to be uneven, most pieces of stainless steel cookware have an aluminum or copper bottom. Some nickel may leach into acidic foods like applesauce, and this presents a problem, especially to people with nickel allergies. We don’t need to worry about chromium, though, because most of us could use a little more of this mineral in our diets.

To minimize leaching, manufacturers sometimes coat steel with porcelain — thus creating enameled cookware. The finish is stain and scratch resistant, and it’s perfectly safe. Manufacturers use no lead in such glazes; while they may use lead in glazes destined for slow-cooking equipment — such as crock pots — they must guarantee that no leaching of the metal will occur. The scary stories we sometimes hear about lead poisoning from ceramic cookware invariably involve improperly manufactured items.

One classic story involves members of a California family who suffered acute lead poisoning after drinking orange juice stored in a ceramic pitcher purchased in Mexico. At first, no one was able to diagnose the condition. Their doctors advised them to leave their house, just in case the problem was environmental. When the family complied, the symptoms disappeared. When they returned to the house, the symptoms reappeared. This cycle occurred several times. Then the family called in a chemist, who quickly realized that the source of the problem was the lead glaze on the juice pitcher. Obviously, they should have consulted a chemist sooner.

So what is the best cookware? The answer depends on one’s personal preference and one’s pocketbook. Trained French chefs worship copper. But for ordinary kitchen chemists like me, a stainless steel pan with a thick aluminum bottom is just fine. Anodized aluminum is also excellent. Nothing sticks to it, it cannot be scratched, and it’s a snap to clean. And, as far as concerns about Alzheimer’s disease go, I’ve been cooking with aluminum pots all my life, and I can’t remember experiencing any problems.

I am nervous about nerve gas. It is a terrible weapon, and it’s not beyond the grasp of terrorists. In 1939, a German chemist named Gerhard Schrader discovered the first nerve gas. Searching for better methods to control insects, he chanced upon a substance that had greater insecticidal activity than anything he had ever seen. He named the new compound “tabun” and envisioned a breakthrough for agriculture. Hitler, however, had something else in mind for the substance. If it could kill pests, it could also kill people. A terrible new weapon was born.

Tabun is a colorless, odorless, relatively volatile liquid. Exposure to a few milligrams is enough to cause death. It penetrates intact skin without any irritating effect, so that a person can unknowingly absorb a fatal dose. The term “nerve gas” was used to describe the substance because of its mechanism of action. Tabun interferes with the way information is transmitted from one nerve cell to another. Such transmission involves the release of chemicals called neurotransmitters from nerve endings; these then migrate across the tiny gap that separates nerve cells, known as the synapse. A neurotransmitter stimulates an adjacent cell by fitting into a receptor site on its surface, very much the way a key fits into a lock. This cell then releases a neurotransmitter, which stimulates the next cell, and thus the message is propagated. The specific neurotransmitter involved in the nerve gas story is acetylcholine.

Once acetylcholine has carried out its job of triggering a reaction in an adjacent cell, an enzyme present in the synapse decomposes it. Overstimulation is therefore prevented. It is this enzyme, acetylcholinesterase, that nerve gas deactivates. The result is overstimulation of the nervous system, eventually leading to convulsions, paralysis, and respiratory failure. The first symptoms of exposure generally include constriction of the pupils, dimming of vision, vomiting, sweating, defecation, the release of secretions from the nose, eyes, mouth, and lungs, and muscle twitching. Inhalation of the gas causes death within minutes, but the effects of liquid exposure may be delayed as much as eighteen hours.

By the end of World War II, the Germans had developed sarin, a nerve gas far more potent than tabun. The chemistry was relatively simple: methylphosphonyl difluoride mixed with rubbing alcohol. But how could they safely store such a ferociously toxic substance? With the introduction of binary weapons after the war, the German military devised an ingenious solution to this problem. The actual mixing of the gas would take place inside a missile or artillery shell after launch. The two chemicals would reside in compartments separated by a barrier designed to rupture upon acceleration, after the projectile had been fired. During flight, the shell or missile would rotate at fifteen thousand revolutions per minute; the components would blend together, forming sarin.

Unfortunately, terrorist groups can obtain the chemicals required to make sarin with relative ease. They can synthesize the key component, methylphosphonyl difluoride, from dimethyl methylphosphonate, which is commercially available since it is widely used to make flame retardants. These terrorists may not have the technology to design a sophisticated binary weapon, but this is not really necessary. In 1995, terrorists pulled off an attack in the Tokyo subway using a primitive system that involved puncturing two plastic bags containing the required chemicals and mixing them. Luckily, the mixing was not very effective, or the death toll would have been much higher than twelve. But even this crude delivery system injured over five thousand people.

The main defense against nerve gas is protective apparel. Gas masks with charcoal filters can reduce the concentration of the gas in inhaled air by a factor of about 100,000. Specially made military protective clothing impregnated with charcoal is also available. The surface of the fabric is treated with a wetting agent that causes droplets to spread out, enhancing evaporation. Since nerve gases break down rapidly in alkaline solution, decontamination of exposed surfaces with hypochlorite (bleach) or bicarbonate (baking soda) is at least a theoretical possibility. The military distributed decontaminating powders incorporating such chemicals to populations at risk of attack during the Gulf War.

Scientists have investigated antidotes for nerve gas poisoning extensively. Since the 1930s, the first line of defense after exposure has been the atropine injection. This compound is an acetylcholine antagonist, because it dislodges acetylcholine from receptor sites, reducing the risk of overstimulation. U.S. military personnel during the Gulf War carried three automatic injectors loaded with two milligrams of atropine each; several doses may be required to reduce the severity of the symptoms caused by exposure.

An atropine injection alone is effective for only a short time. Since the nerve gas deactivates acetylcholinesterase, the concentration of acetylcholine will keep increasing, and it will eventually overpower the protective effect of atropine. One must administer a second substance, pralidoxime chloride, to release the nerve gas from the enzyme and destroy it. This, too, is available in automatic injectors, and the Gulf War soldiers carried three of them for concurrent use with atropine.

Even those who survive nerve gas exposure may suffer convulsions, and for this reason an automatic injector containing ten milligrams of diazepam (Valium) is generally used with the third dose of atropine. Unfortunately, the timing of these injections is critical. By the time a victim recognizes the signs of nerve gas intoxication, it may already be too late to take the antidote. Even survivors may not get off scot-free: researchers working with animals report some evidence that sarin can cause cancer.

While, in theory, the antidotes should work, no one has actually ever tried them under battle conditions. But, sometime, somewhere, the test will come, because, as we have seen, sarin is not all that hard to synthesize. And we know what terrorists are capable of.