The Invention of Nature

He had described the rapids of the Orinoco which were ‘illuminated by the rays of the setting sun’ as if a river made of mist were ‘suspended over its bed’. Though he always measured and recorded, Humboldt also wrote of how ‘coloured bows shine, vanish, and reappear’ at the great rapids and of the moon ‘encircled with coloured rings’. Later, he delighted in the dark river surface which during the day reflected like a perfect mirror the blossom-loaded plants of the riverbanks and at night the southern star constellations. No scientist had referred to nature like this before. ‘What speaks to the soul,’ Humboldt said, ‘escapes our measurements.’ This was not nature as a mechanistic system but a thrilling new world filled with wonder. Seeing South America with the eyes that Goethe had given him, Humboldt was enraptured.

Less pleasing was the news he received from the missionaries whom they met en route: apparently the fact that the Casiquiare connected the Amazon and the Orinoco had been well known in the region for several decades. The only thing left for Humboldt was to map the course of the river properly. On 11 May 1800 they finally found the entrance to the Casiquiare. The air was so saturated with humidity that Humboldt could see neither the sun nor the stars – without which he would not be able to determine the geographical position of the river, and hence his map would not be precise. But when their Indian guide predicted clear skies, they pressed on north-east. During the nights they tried to sleep in their hammocks along the riverbanks but found rest almost impossible. One night they were chased out by columns of ants marching up the ropes of their hammocks, and on others they were tormented by the mosquitoes.

As they paddled on, the vegetation grew denser. The embankment was like a living ‘palisade’, as Humboldt described it, green walls covered in leaves and lianas. Soon they couldn’t find a place to sleep at all any more, nor even get out of the canoe to go ashore. At least the weather was improving and Humboldt could take the necessary observations for his map. Then, ten days after they had first entered the Casiquiare, they reached the Orinoco again – the missionaries had been correct. It had not been necessary to travel all the way south to the Amazon, because Humboldt had proved that the Casiquiare was a natural waterway between the Orinoco and the Rio Negro. Since the Rio Negro was a tributary of the Amazon, it was clear that the two great river basins were indeed connected. And though Humboldt had not ‘discovered’ the Casiquiare, he had made a detailed map of the complex tributary system of these rivers. This map was a great improvement on all previous ones, which, he said, were as imaginary as if they ‘had been invented in Madrid’.

On 13 June 1800, having raced downstream towards the north and then east along the Orinoco for three more weeks, they arrived in Angostura (today’s Ciudad Bolívar), a small bustling town on the Orinoco, a little less than 250 miles south of Cumaná. After 1,400 miles and seventy-five days of gruelling river travelling, Angostura with its 6,000 inhabitants seemed like a metropolis to Humboldt and Bonpland. Even the humblest dwelling appeared magnificent and the smallest convenience became a luxury. They cleaned their clothes, sorted their collections and prepared for their ride back across the Llanos.

They had survived mosquitoes, jaguars, hunger and other dangers but, just as they thought the worst was over, Bonpland and Humboldt were suddenly struck down by a violent fever. Humboldt recovered quickly, but Bonpland was soon fighting for his life. When the fever slowly ebbed after two long weeks, it was replaced by dysentery. Embarking on the long journey across the Llanos in the middle of the rainy season would be too dangerous for Bonpland.

They waited a month in Angostura until Bonpland had regained enough strength for the journey to the coast from where they intended to catch a boat to Cuba and from there to Acapulco in Mexico. Once again their trunks were loaded on to mules, with cages of monkeys and parrots dangling off their sides. The new collections had added so much weight to their luggage that progress was now tediously slow. At the end of July 1800, they stepped out of the rainforest into the open space of the Llanos. After weeks in the dense jungle where the stars appeared as if viewed from the bottom of a well, it was a revelation. Humboldt felt a sense of freedom that made him want to gallop across the wide plains. The sensation of ‘seeing’ everything around him felt completely new. ‘Infinity of space, as poets have said in every language,’ Humboldt now mused, ‘is reflected in ourself.’