The Invention of Nature

Over the next few years, Humboldt regularly travelled to Jena and Weimar whenever he found time. Humboldt and Goethe went on long walks and dined together. They conducted experiments and inspected the new botanical garden in Jena. An invigorated Goethe moved easily from one topic to another: ‘early morning corrected poem, then anatomy of frogs’ was a typical entry in his diary during one of Humboldt’s visits. Humboldt was making him dizzy with ideas, Goethe told a friend. He had never met anyone so versatile. Humboldt’s drive, Goethe said, ‘whipped the scientific things’ with such speed that it was sometimes hard to follow.

Three years after his first visit, Humboldt arrived in Jena for a three-month break. Once again Goethe joined him there. Instead of going back and forth to Weimar, Goethe moved to his rooms at the Old Castle in Jena for a few weeks. Humboldt wanted to conduct a long series of experiments on ‘animal electricity’ because he was trying to finish his book on the subject. Almost every day – often with Goethe – Humboldt walked the short distance from his brother’s house to the university. He spent six or seven hours in the anatomy theatre as well as lecturing on the subject.

When a violent thunderstorm hit the area one warm spring day, Humboldt dashed outside to set up his instruments in order to measure the electricity in the atmosphere. As the rain lashed down and thunder reverberated across the fields, the small town was illuminated by a wild dance of lightning. Humboldt was in his element. The next day, when he heard that a farmer and his wife had been killed by the lightning, he rushed over to obtain their corpses. Laying out their bodies on the table in the round anatomy tower, he analysed everything: the man’s leg bones looked as if they had been ‘pierced by shotgun pellets!’, Humboldt noted excitedly, but the worst damage was to the genitals. At first he thought that the pubic hair might have ignited and caused the burns, but dismissed the idea when he saw the couple’s unharmed armpits. Despite the increasingly putrid smell of death and burned flesh, Humboldt enjoyed every minute of this gruesome investigation. ‘I cannot exist without experiments,’ he said.

Humboldt’s favourite experiment was one that he and Goethe discovered together by chance. One morning Humboldt placed a frog’s leg on a glass plate and connected its nerves and muscles to different metals in sequence – to silver, gold, iron, zinc and so on – but generated only a discouraging gentle twitch in the leg. When he then leaned over the leg in order to check the connecting metals, it convulsed so violently that it leapt off the table. Both men were stunned, until Humboldt realized that it had been the moisture of his breath that had triggered the reaction. As the tiny droplets in his breath had touched the metals they had created an electric current that had moved the frog’s leg. It was the most magical experiment he had ever carried out, Humboldt decided, because by exhaling on to the frog’s leg it was as if he were ‘breathing life into it’. It was the perfect metaphor for the emergence of the new life sciences.

In this context they also discussed the theories of Humboldt’s former professor, Johann Friedrich Blumenbach, about the forces that shaped organisms – the so-called ‘formative drive’ and ‘vital forces’. Fascinated, Goethe then applied these ideas to his own about the urform. The formative drive, Goethe wrote, triggered the development of certain parts in the urform. The snake, for example, has an endlessly long neck because ‘neither matter nor force’ had been wasted on arms or legs. By contrast, the lizard has a shorter neck because it also has legs, while the frog has an even shorter neck because its legs are longer. Goethe then went on to explain his belief that – contrary to Descartes’s theory that animals were machines – a living organism consisted of parts that only function as a unified whole. To put it simply, a machine could be dismantled and then assembled again, while the parts of a living organism worked only in relation to each other. In a mechanical system the parts shaped the whole while in an organic system the whole shaped the parts.

Humboldt widened this concept. And although his own theories of ‘animal electricity’ were eventually proved wrong, they did give him the foundation of what would become his new understanding of nature.¹ Whereas Blumenbach and other scientists applied the idea of forces to organisms, Humboldt applied them to nature on a much broader level – interpreting the natural world as a unified whole that is animated by interactive forces. This new way of thinking changed his approach. If everything was connected, then it was important to examine the differences and similarities without ever losing sight of the whole. Comparison became Humboldt’s primary means of understanding nature, not abstract mathematics or numbers.