by Vanessa Everts and Pauline van Lynden
Visual Legacy, 2018, 240 pp, rrp €39,95
ISBN 978 90 811850 5 9 English
ISBN 978 90 811850 6 6 Dutch
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Iron is everywhere around us and within us. It is vital to organisms – it colours our blood as well as the earth. We admire people with an iron constitution and a steely determination, and almost everything we do involves iron and steel in some form. Yet we hardly seem to realise how reliant on this ancient metal we are. Without iron there would be no cars, no cargo ships, no railways. Most bridges and buildings would crumble. Agriculture would have stayed small and we would have had no Industrial Revolution. There would be no energy networks, no elevators, no oyster-shucking, no piano music... And paints would not have become what they are today. This book describes the fascinating life of iron and our life with iron and steel, from the earliest days of our planet to our growing ironworking techniques and the miracles that are achieved through metallurgy today. It delves into an exceptional combination of qualities no other material offers us and shows us why, through millenia of rust, recycling and reinvention, this tough stuff continues to reveal enormous potential for our world and our future.

"But dear lady, that isn't the same iron!" So said a shocked workman in a sandblasting yard when I told him about this book. It may by now take a little stretch of the imagination, but the iron we take from the earth and are able to transmute into ever finer steel, whose innermost properties we are growing to understand on an ever-deeper level, is exactly the same iron we have in our blood.

We cannot live without iron. All vertebrates and some invertebrates need iron to bind and transport oxygen from our lungs to our cells and to collect carbon dioxide from them, taking this back to our lungs for release when we breathe out. Most of our body's iron is contained in red blood cells, bound into haemoglobin, the transport protein that fills about a third of our red blood cells. If you don't have enough iron in your body you cannot make enough haemoglobin and as a result you are likely to feel tired and weak as your cells are insufficiently energised by oxygen. Iron (and oxygen) can also be bound into myoglobin in our muscle cells. Both haemoglobin and myoglobin owe their colour to iron. Some invertebrates like crabs and squids use copper as we do iron and as a result their blood is blue-green, the colour of oxidised copper.

Wonderfully, our cells reuse the iron we absorb from food numerous times. Red blood cells have a limited life span and when their time comes these cells are eliminated by other cells called macrophages (Greek for 'big eaters'), but not before the latter have saved the iron, which they pass on to new red blood cells when these are grown in the bone marrow. Our friend ferroportin is again responsible for getting the iron from the macrophages into the new red blood cells. Small miracles happen every day.

Text and images © Vanessa Everts and Pauline van Lynden, 2018