Hailed as the greatest scientist of his time, Alexander von Humboldt (1769-1859) had the tiniest handwriting I have ever seen. One of the most fascinating pages in Andrea Wulf’s new biography shows his lecture notes: a jumble of cards, envelopes, and scraps of paper, stacked on top of each other, with remnants of wax on them. They provide a window into a restless mind that worked not unlike the environments that Humboldt described with great beauty and clarity, a mind that would, from a multitude of finely observed details, assemble a picture of the whole—ein Naturgemälde, a complete picture of nature, as Humboldt called it.
Wulf relates that when Humboldt wrote his multivolume masterwork, Cosmos (the “opus of my life”), he relied on a system of boxes with envelopes, each of which contained important letters, annotated by Humboldt himself, pages ripped from books, maps, and other related material. It was a mystery to his friends how his books emerged from such chaos. The unsung heroes of Humboldt’s life are, to my mind, the printers who transformed his hieroglyphs into some of the most glorious works of natural history writing ever published.
When I was working on a biography of the Swiss-American scientist Louis Agassiz, one of Humboldt’s many disciples, I spent hours poring over the latter’s letters in archives. I remember the overwhelming feeling of happiness that took hold of me, as if I had just partaken of a great mystery, when first single letters, then words, then entire sentences emerged from what had originally seemed like an abstract pattern of tiny tracks, as if a small bird had stepped into an inkwell and then performed a madcap dance on the page. Since I had worked so hard to gather their meaning, each of these letters became a precious possession, something I would carry with me for days afterwards. The Humboldt who spoke in these letters was not the man Wulf paints for us, relying mostly on his brother Wilhelm’s and his sister-in-law’s characterizations: insatiable in his thirst for knowledge, oblivious in his personal relationships, and so obsessed with nature that he didn’t mind his loneliness.
“Your glaciers make me shudder,” he told the much younger Agassiz when the latter was spending too much time high up in the Bernese Alps. A creature of the equator, Humboldt was appalled by the mere thought of spending one’s days surrounded by ice. But what he really meant was a different kind of coldness, one that resided inside Agassiz: If he didn’t return home soon, to his family and to his original work—Agassiz was studying fossil fish when he became interested in the movements of glaciers—Humboldt would begin to haunt him, reincarnated as one of Agassiz’s neglected specimens. Be a father to your family, he said to Agassiz, rather than to your students—poignant, tender, moving words coming from someone who never had children himself. No one in Agassiz’s life had ever spoken to him that way, and no one would ever again. (Agassiz didn’t listen, and his wife left him.)
Humboldt’s fame encompassed the world: Mountains, towns, bays, and a river (over 300 miles long, with lots of fish in it, as Humboldt joked), at least three universities, schools, and a dozen species were named after him. Today, contends Wulf, we barely remember him or what he did—a puzzling statement, given that one of the world’s largest academic exchange foundations, with a network of more than 25,000 alumni, is named after him. So many biographies of Humboldt were written during the last 150 years that the Dutch historian Nicolaas Rupke recently published what he called Humboldt’s “metabiography,” a study of the many different versions of the German scientist that had been invented since his death.
Perhaps the problem with remembering Humboldt is that he is not associated with a specific discovery, an iconic moment or powerful story that would define him, like Isaac Newton watching the apple fall or Charles Darwin hopping around on the Galápagos, bagging his finches. Humboldt remains a mystery, even in Wulf’s often-vivid re-creation. Here was a man who barely slept and nevertheless remained hale and hearty well into his old age, who talked incessantly but remained silent about his own personal life, who claimed that he had no need for intimacy yet left us with some of the most sensual descriptions of tropical nature we have.