The Signature of All Things

prejudice, but also because of a lingering preference for bleeding their patients, rather than treating them with queer powders. In addition, the extraction of medicine from the cinchona was a complicated science. There were some seventy varieties of the tree, and nobody knew exactly which barks were the most potent. One had to rely on the honor of the bark collector himself, who was usually an Indian six thousand miles away. The powders one often encountered as “Jesuit’s bark” in London pharmacies, smuggled into the country through secret Belgian channels, were largely fraudulent and ineffective. Nonetheless, the bark had at last come to the attention of Sir Joseph Banks, who wanted to learn more about it. And now—with the merest hint of potential riches—so did Henry, who had just become the leader of his own expedition.
    Soon Henry was moving through Peru like a man goaded by the tip of a bayonet, and that bayonet was his own furious ambition. Ross Niven, before dying, had given Henry three sound pieces of advice about traveling through South America, and the young man wisely followed them all. One: Never wear boots. Toughen up your feet until they look like the feet of an Indian, forsaking forever the rotting embrace of wet animal hide. Two: Abandon your heavy clothing. Dress lightly, and learn to be cold, as the Indians do. You’ll be healthier that way. And three: Bathe in a river every day, as the Indians do.
    That constituted everything Henry knew, aside from the fact that cinchona was lucrative, and that it could be found only in the high Andes, in a remote area of Peru called Loxa. He had no man, map, or book to further instruct him, so he solved it on his own. To get to Loxa, he had to endure rivers, thorns, snakes, illness, heat, cold, rain, Spanish authorities, and—most dangerous of all—his own team of sullen mules, ex-slaves, and embittered Negroes, whose languages, resentments, and secret designs he could only begin to guess at.
    Barefoot and hungry, he pushed on. He chewed coca leaves, like an Indian, to keep up his strength. He learned Spanish, which is to say that he stubbornly decided that he could already speak Spanish, and that people could already understand him. If they could not understand him, he shouted at them with increasing force until they did. He eventually reached the region called Loxa. He found, and bribed, the cascarilleros , the “bark cutters,” the local Indians who knew where the good trees grew. He kept searching, and found even more hidden groves of cinchona.
    Ever the orchardman’s son, Henry quickly realized that most of the cinchona trees were in poor condition, sick and overharvested. There were a few trees with trunks as thick as his own midsection, but none any bigger. He began to pack the trees with moss, wherever the bark had been removed, to allow them to heal. He trained the cascarilleros to cut the bark in vertical strips, rather than killing the tree by horizontally banding it. He severely coppiced other sick trees, to allow for new growth. When he became sick himself, he kept on working. When he could not walk from illness or infection, he had his Indians tie him to his mule, like a captive, so he could visit his trees every day. He ate guinea pigs. He shot a jaguar.
    He stayed up in Loxa for four miserable years, barefoot and cold, sleeping in a hut with barefoot and cold Indians, who burned manure for heat. He continued to nurse the cinchona groves, which legally belonged to the Spanish Royal Pharmacy, but which Henry had silently claimed for his own. He was far enough back in the mountains that no Spaniard ever interfered with him, and after a time the Indians weren’t bothered by him, either. He gleaned that the cinchona trees with the darkest bark seemed to produce a more potent medicine than the other varieties, and that the newest growth produced the most powerful bark. Heavy pruning, therefore, was advisable. He identified and named seven new species of cinchona, but most of themhe considered useless. He focused his attention on what he called cinchona roja— the red tree, the richest. He grafted the roja onto the root stock of more sturdy and disease-resistant varieties of cinchona in order to produce a higher yield.
    Also, he thought a great deal. A young man alone in a high and distant forest has plenty of time to think, and Henry formulated grand theories. He knew from the late Ross Niven that the trade in Jesuit’s bark was