Elements from Hell: An exhibition of molecules that are mainly malevolent

The road to hell is paved with good intentions . . . so the old saying goes. In this Gallery I want to show you that this can be indeed true, but it is also true that the road to hell can be paved with evil intentions—sometimes all the way down to the pit of fire. Elements cannot really be described as coming from hell, nor can molecules, but they can produce effects that can only be described as satanic. Some elements that exist naturally can be very toxic, such as beryllium and lead, and the same is true of some natural molecules, such as atropine. We have seen in other Galleries that when chemists discover a natural molecule which has desirable properties, it is often possible to make a safer version that retains these properties, or even enhances them, while unwanted side-effects can be eliminated or at least toned down. The opposite is also possible. If the desired property of a molecule is its ability to kill, then it is possible to refine that aspect. What was merely dangerous can be made maliciously deadly. We begin our tour of the portraits of Gallery 8 with an inspection of one of these terrible molecules. Could Adolf Hitler have saved his Third Reich from defeat? Quite possibly. What he needed was a secret weapon to wipe out the Allied troops when they invaded the Normandy beaches of northern France on D-day, 6 June 1944. Then with a quick victory in the west he could have rushed his troops to meet the oncoming onslaught of Russian armies from the east, and maybe even have wiped out those invaders as well. Hitler was fond of secret weapons. Some, like the jet fighter, the V1 flying bomb and the V2 rocket bomb, were triumphs of engineering and did a lot of damage, but they were generally developed too late to save his empire. In fact Hitler had one secret weapon that was very cheap and easy to make, and that would have stopped advancing armies dead, but he never used it.

Material progress and immaterial observations: An exhibition of molecules that make life a little easier

You may think of polymers as entirely manufactured and therefore unnatural, but they are often the chemists’ attempts to supplement and improve on the biological polymers that nature produces. Cotton, ivory, leather, linen, paper, rubber, silk, wood and wool are wonderful materials made from the biological polymers that plants and animals produce, and which have evolved to serve such useful ends as providing protective outer layers, insulation, reinforcement, weaponry and so on. Humans learned that with a little modification they could turn these polymers into quite useful articles, such as briefs and briefcases, condoms and tea cosies, tickets and toothpicks. Sometimes we want polymers with features that never evolved in nature, such as non-cracking insulation for electric cable, clothes that can be unpacked after a long voyage and still be without creases, or pans in which to fry eggs without them sticking. For these polymers we have had to look to chemists. Most of the portraits in this Gallery are of these kinds of polymers—materials that do not have natural equivalents. Polymers are rather special kinds of molecules consisting of long chains, usually made up of carbon atoms, to which other atoms, such as hydrogen, fluorine and chlorine, are attached. The older name for polymers is plastics, and you probably know several of them by name— polythene, polystyrene, Teflon, Orion—but these are only a few of the many that now play an important role in our lives. Whatever role polymers play, they cause many of us to adopt quite strong attitudes towards them. A few of us admire them, many of us ignore them, but a growing number despise them and a few abhor them and will avoid them at all costs. To a chemist, this opposition to polymers seems rather strange. By the time you come to the end of this exhibition I hope that visitors with strong views will have seen enough to persuade them to change their mind. Attitudes towards plastics have changed over the past half-century. In the 19305, when cellophane, PVC, polystyrene, Perspex and nylon were launched, plastics were welcomed.

Landscape room: environmental cons, concerns and comments: An exhibition of molecules that stalk the world

A hundred years ago, if you talked about protecting the environment you meant preventing floods or forest fires. Homes and farms could be ruined and families wiped out by a flash flood, a surge tide, or a raging fire. Meanwhile in industrial regions the skies were polluted with fumes, smoke and smog, rivers were little more than open drains and slag was piled up in great heaps. People complained but there was little they could do, because their livelihoods depended on the very industries which were causing the pollution. Excesses were curbed, but change was painfully slow. Fifty years ago, when you spoke of protecting the environment you meant controlling urban sprawl and cleaning up the wastes of industry. The climate of opinion now favours quicker changes, and much has been achieved since then: slag heaps have been sculpted into grassy knolls, derelict sites have been demolished and turned into sport centres or superstores, rivers now support fish and wildlife abounds on their banks. The belching smoke and choking fogs of coal-burning industries are only memories. And while the air in cities is now fouled by traffic fumes, there are signs that this pollution too will disappear as cars become cleaner. People today have other environmental concerns. They want action taken on different kinds of pollution. It is not enough to pull down old factories, gas works and foundries and to turf over the site: we want the soil beneath to be decontaminated too, so that homes can be built there and children can play safely in gardens. People want power to be generated without causing acid rain. They want all rivers and lakes to be so clean that people can fish from them or swim in them. When it comes to breathing, we have little choice. The air we breathe comes with the neighbourhoods in which we live and work. Clearly, we have some control: we can avoid traffic fumes, and change the ventilation of the rooms we are in, but even so the mixture that we are taking in is still a cocktail of gases, some of which are not natural, and some of which may be hurting us.

Testing your metal: An exhibition of the metals which our body must have

Ask people which metals are essential for healthy living and I suspect most would say zinc and iron. Some might mention sodium and potassium, although sodium is often regarded as something deleterious to healthy living; and a few people will know that calcium is a metal also, and important. In fact the human body needs fourteen metal elements to function properly. But for every metal that we do need, there is another that our body contains that we could well do without. These metals serve no known purpose, but they come with the food we eat, the water we drink, and the air we breathe and our body absorbs them, mistaking them for more useful elements. As a result we find that the average adult contains measurable amounts of aluminium, barium, cadmium, caesium, lead, silver and strontium. There are also trace amounts of many others, including gold and uranium. Because strontium so closely resembles calcium we absorb a lot of this element, and the average person has about 320 mg in their body, far more than of many of the essential elements. On the other hand the weight of gold in the average person is only 7 mg, worth but a few pence, and the weight of uranium is only 0.07 mg, although turned into pure energy this could drive your car for five kilometres. Our body tends to retain these unwanted intruders either in our skeleton, as in the case of uranium which has a special propensity to bind to phosphate, or in our liver which has proteins that can trap metals like gold. The table below lists the amounts of the essential 14 metals in the average adult—someone who weighs 70 kg (155 pounds). As we would expect, calcium heads the list because, along with phosphate, it is what makes up the bones of our skeleton, which weighs 9 kg on average. Of this, i kg is calcium and 2.5 kg is phosphate. In fact 99% of the body's calcium and 85% of its phosphate is in the skeleton. Bone also contains water and the protein collagen, plus the elements sodium, potassium, iron, copper and chlorine.

We’re on the road to nowhere: An exhibition of molecules to transport us

The rays of the Sun, and the motions of the Moon and Earth, provide energy in abundance. Light from the Sun is absorbed by plants on land and algae in the sea and is used to convert carbon dioxide into high energy carbohydrates, which in turn become oils. Together these provide most of the food energy for animals like ourselves. We can also harvest plants and trees and burn them to release this energy as heat. The sunlight which falls on barren terrain, or on the roofs of buildings, we can also gather by using solar panels to heat water or to make electricity. The sunlight which falls on the oceans leads to evaporation of water which is precipitated on land, and this too we can use to generate hydroelectricity. The Earth itself is a vast reservoir of heat below the crust, but this is not so easily tapped—although in parts of the world, such as New Zealand, hydrothermal heat is an important source of power. We can extract energy from the effects of the Earth’s daily rotation, partly through the weather systems this produces, by using windmills, and possibly through the rise and fall of sea levels, by using tidal barriers and wave power. These sources of clean energy should be able to provide all the fuel and electricity for a sustainable human population of several billion, provided we did most of our travelling on foot or by bicycle. How much these natural renewable sources could really provide is debatable, but we have the means to utilize them so they could supply enough food and energy for a world population of two or three billion, and at a level which allows for most of the high-tech living that we now take for granted. It might even be possible for most families to run a car, provided they were content to travel only a couple of thousand miles a year in it. The trouble is that there are already six billion of us, and forecasts are that this will reach ten billion by the middle of the next century. Most of these people will no doubt aspire to owning a car.

Home, sweet home: An exhibition of detergents, dangers, delights and delusions

Few people today lead home-centred lives, and perhaps that’s how it should be. For earlier generations the home was all important: it was a place of comfort after a hard day’s work, a place to be proud of, a place of love and security for young children—and possibly a place of drudgery, boredom, quarrels and abuse. But whatever a home was, it was a place which chemistry was to transform, so that today it is cleaner, healthier, safer to live in, and with some remarkable labour-saving gadgets and entertainment facilities. It is cleaner because of detergents, healthier because of disinfectants and safer because the chemicals we use may be protected by other chemicals, as we shall see. Throughout the 19605, 708 and 8os the use of detergents was portrayed by some as almost wanton pollution of rivers and lakes. The chemicals that lift grease and dirt from dishes, clothes and even our own bodies were accused of causing ‘eutrophication’: the imbalance in rivers, lakes or inland seas that produces an excess of slimy algae or weeds. The main culprit was said to be phosphate in detergents, but even the surfactants they relied on for their cleaning ability were under a cloud, because these were produced from oil. Such was the odium under which detergents laboured that companies strove to produce ‘green’ alternatives that were phosphate-free. Unfortunately many consumers did not like them, but their rejection in the end hardly mattered because it turned out that phosphates were not so environmentally damaging after all. Detergents are made up of many components, but two are worth a closer look: surfactants, which dissolve grease, and phosphates, which soften the water. It is not difficult to find something good to say about them both of them. During the Gulf War of 1991, millions of barrels of crude oil were deliberately released by the Iraqi invaders into the waters of the Persian Gulf. As usually happens, it was the local birds who bore the brunt of this ecological vandalism.

Starting lives, saving lives, screwing up lives: An exhibition of molecules that can help and harm the young

In this gallery we will look at the portraits of molecules which can affect us very profoundly, and not only ourselves, but also the life we carry inside us, or the life we would like to create. In a private room at the end of the gallery are a few portraits that were not thought suitable for public exhibition, but which selected individuals will be allowed to view. These are molecules that are deemed undesirable, but their eradication is proving difficult, if not impossible. Few things are more important than creating new life, and yet nature has an almost cavalier attitude to the process, investing in gross overproduction of the raw materials necessary. Women have the ability to produce around three hundred eggs in a lifetime, and men to manufacture three hundred million sperm a week. Despite this abundance the human population has been kept in check in many ways—high infant mortality, famine, disease, war; but even so, today we have a world that is overpopulated with humans. This has come about through the success of science, which has lifted the first three of these natural scourges, although it has made the fourth much worse. Sadly science has so far not elicited the response of better birth control in many parts of the world, but it has made it possible to plan parenthood carefully. Science has also made it possible to ensure that if you decide to have a baby, then the baby you bring into the world should be perfect. The only prayer that potential parents in developed nations deem necessary is ‘please let our baby be all right.’ There are a few simple precautions that a woman can take to ensure her baby has a good chance of avoiding some risks that would seriously affect it. In this part of the gallery there are two molecules that she needs to think about. Folic acid is found in plants, animals and microorganisms such as fungi and yeasts. It is present in grass, butterflies’ wings and fish scales. Humans need it also, as an essential component for several metabolic processes.

Nearly as nature intended: An exhibition of some curious molecules in the foods we eat

There are scores of myths surrounding the things we eat: chocolate is almost addictive; Coca-Cola is just a concoction of chemicals; garlic wards off heart disease and cancer; an aspirin a day keeps the doctor away. None of these statements is true, but they contain a germ of truth. In this gallery we can inspect the portraits of some of the natural and unnatural chemicals which a normal diet contains. The pleasures of eating are sweet but fleeting, while the warnings about food seem bitter and never-ending. The warnings we should heed are those of professional dietitians, the front-line troops who are fighting the war against poor nutrition and unbalanced diets. While they help the people who are referred to them, the rest of us only hear their advice second-hand, and even then we do not heed it—which may explain why one person in five is now classed as obese (33% or more overweight) i. the USA, and one in ten in Britain. Behind the front-line dietitians is a regiment of armchair food commanders who offer their advice to anyone who listens. Often it is soundly based, telling us how to lose weight and still be properly nourished, but a lot is rather unhelpful, merely condemning some popular foods as ‘junk’ without explaining why they are so (although this term is generally taken to mean that they contain too much sugar, salt, saturated fats and additives). Examples of junk food are chocolate, colas, hamburgers and french fries. Sadly the healthy alternatives, such as raw celery, mineral water and lentils, lack appeal for many, and especially for children. Alongside claims about junk food come more dire warnings about the chemicals that are present in other foods, and especially if these have been added merely to make food look and taste more tempting, or if they are there as contaminants that come from pesticides and processing. Surprisingly, most food-related illness comes not from these, but from micro-organisms such as bacteria and fungi, and we are most at risk when we eat food that has not been properly stored or prepared. Ideally food should be free of all dangerous impurities, be they bacteria, fungi or chemicals.