Making Bread from Air

Hands held too tight

Combine piece four's hand-holding with piece five's 'travel in pairs' and the answer appears. Nitrogen in the air travels as a pair, and the two hold each other with three hands each — one of the tightest grips in nature. Plants cannot pry it open.

So farming was always a fight for nitrogen. Only tiny creatures living on the roots of beans and a few other plants could open that grip, so people planted beans to rest the soil, and dug seabird droppings from distant islands and shipped them home. That ran out too. In the early 1900s people feared famine.

To take apart — first, electricity

A new way of taking things apart had arrived a century earlier: electricity.

In 1800 an Italian stacked silver and zinc discs with salt-soaked cloth between them, layer on layer. Current flowed — not in one flash but steadily. The first battery. Until then electricity was a spark stored in a jar and released once; now it was a stream.

Bread from air

Nitrogen's grip would not open even for electricity. In the early 1900s a German chemist found another road: squeeze very hard, as in piece five, heat it, and let iron powder help. Then nitrogen lets go and takes hydrogen's hand instead. Ammonia — the raw material of fertiliser.

What works in a laboratory is not what works in a factory. Another engineer spent years more building vessels that could stand 200 atmospheres. In 1913 the plant started running.

A little further in

The other work of the same hand

A few years later the same man led the making of poison gas in a war. The hand that fed billions and the hand that killed thousands were one hand. His wife, also a chemist, died soon after.

Chemistry is the craft of taking apart what is joined and joining what was taken apart. What to take apart and what to join, chemistry does not decide. People do. That is what this series leaves you with at the end.

Looking back over eight pieces

The candle did not vanish; it grew heavier (1). Matter was grains (2). The kinds of grain repeated like a song (3). Grains have hands and three ways of holding (4). Invisible grains were counted with a ruler and a scale (5). Mixing changes and separating purifies (6). Fire too fast is an explosion (7). And bread came out of air (8).

Not one formula was used. Yet everything chemistry does appeared: letting go of hands, taking hold of hands. From a candle to the rice in your bowl.

The question that remainsThe same craft fed billions and killed thousands. Is a technique then neither good nor bad — or both at once?