Excerpted from Chapter Thirteen, “Human Soil.”

The dead Japanese carpenter was sprawled on a dirt road on the northern edge of the island of Hawaii, a half-burned cigarette smoldering beside his head. His distraught wife claimed that two white males in rubber overcoats had ambushed them and murdered her husband. She told the story to a doctor, L. S. Thompson, who had seen the woman leading a bloodstained horse. Thompson did not believe the woman, whose name was Kamaka. He sent for the sheriff, and Kamaka was arrested.

The next story she told differed from the first. She and a Hawaiian farmer named Keanu had become lovers, she said. When her husband had discovered the affair, he told Kamaka that they were immediately moving to the other side of the island, far from Keanu. The couple had set out at dawn. Three miles down the road, Keanu rode out from behind a screen of brush and said, “Aloha.”

Kamaka’s husband, known as Charley, answered, “Aloha.”

Keanu stabbed Charley in the face, knifed him at the back of the head, pulled him from his horse and plunged the blade twice into his throat and once into his chest, then stood panting over his victim, who lay facedown in the dirt. “Charley did not say anything after being struck,” Kamaka later testified. “Charley bled.” A jury returned with a guilty verdict in two hours and thirty minutes, with one juror dissenting. At 1 p.m. on August 2, 1884, Marshal William Cooper Parke brought Keanu before Albert Francis Judd, chief justice of the Hawaii Supreme Court. An interpreter asked if the prisoner had anything to say before sentencing.

“I am not guilty,” Keanu replied. “That is all I have to say.”

Judd announced that Keanu was to be “hung by the neck . . . until you are dead. And may God have mercy on your soul!” A reporter from the Advertiser wrote, “During the delivery of the death sentence, the prisoner stood with his eyes cast downward, and apparently never moved a muscle. He evidently anticipated his fate.”

Several weeks after Keanu was condemned to the gallows, Dr. Eduard Arning, a physician working on behalf of the board of health, asked that Keanu instead be handed over to him to use as an “experimental animal.” The men of the government Privy Council agreed to the request. To satisfy his own ethics, Dr. Arning later claimed, he explained in detail to the prisoner what was likely to happen to him. Keanu seemed not to care. In a steady hand Keanu marked his signature on the medical release. “With the prisoner’s permission,” Arning reported, “I commenced operations on the last day of September 1884.”

A horse cart carried Keanu along the narrow causeway away from Oahu Prison. When the buggy reached Kakaako Hospital, an attendant led Keanu to a shed where the doctor waited, along with a frightened nine-year-old girl. Arning told Keanu to sit. A board physician later described Keanu: “48 years old, has physique massive, weight about 250 pounds, broad-shouldered, erect of carriage, 5 feet 10 inches tall.” On a table next to Keanu was a short metal pipe fitted with a rubber hose, an apparatus invented by a German chemist who taught at the University of Heidelberg, where Arning had attended medical school. Arning was twenty-nine years old, a blue-eyed, golden-haired young doctor so intoxicated by the new science of microbes that he appeared to suffer from what was known at the time as “bacteriomania.” While the convict watched, the doctor ignited the Bunsen burner.

Heating a scalpel over the burner, Arning used it to swell a blister on Keanu’s right forearm. He then drew fluid from a leprous ulcer on the girl’s chin, injected it into the blister, and rubbed the remainder onto a patch he had scarified on Keanu’s left earlobe. Next, the doctor washed the girl’s forearm, sprayed it with a diluted mix of carbolic acid, and, using his scalpel blade, split the skin. He sliced free a square of tissue and set it aside. After sewing closed the girl’s wound, Arning turned to Keanu. Opening a deep incision on the Hawaiian’s left forearm, the doctor exposed the marbled belly of the heavy radius longus muscle, which twitched in reflex to the cut. Arning transferred the material and stitched the tissue within the folds of Keanu’s flesh. He swabbed the arm with disinfectant, touched it with ointment, and wrapped it in a sleeve of gauze.

Then he waited.