Toxic Trees and Human Lacquerware

Mummification is the process—natural or artificial—that arrests the decay of tissue after death. The Egyptians hoped it would secure eternal life in the next world; Lenin and Mao simply seem to enjoy having their pictures taken with tourists. Across the globe, bodies have mummified naturally when unique environments halted organic activity and preserved the corpse in remarkably good condition. We see this in the "Indian" mummies of the cold, arid Andes; the tattooed Tocharians of the Tarim Basin; and the ritual victims of Danish peat bogs, where acidic, oxygen-starved waters preserved their tortured forms, granting them a strangely charming bronze hue.

Tollund Man, Denmark, Iron Age.

A "Tocharian" mummy from the Tarim Basin, Xinjiang, China. European features, beard, and tattoos. First millennium BCE.

Despite their varied origins, these mummies share one defining trait: they were all formed after death.

In at least one instance, however, the mummification process began while the subject was still very much alive.

About a thousand years ago, a Buddhist monk named Kūkai returned to Japan after studying in Chang'an, the capital of the Tang Dynasty. Kūkai specialized in what scholars call Esoteric Buddhism, a branch that emphasizes mantras, rigorous mental and physical discipline, visual aids, and the intimate guidance of a master to reach awakening. Tibetan Buddhism is perhaps the best-known example of such a school.

Kūkai (774–835).

Upon his return, Kūkai founded the Shingon school (the name means "True Word"). It survives today as a rare living tradition of Esoteric Buddhism, long after the movement faded in China, India, and Central Asia.

But what does the Shingon sect have to do with mummies? Within certain monastic communities, primarily those associated with Shingon, a practice emerged known as Sokushinbutsu—literally, "becoming a Buddha in this very body." The process was a grueling ordeal lasting roughly a decade. The goal was to prevent the body from decomposing after death, preserving it whole as a testament to the monk's enlightenment.

The Sokushinbutsu process consisted of three stages, each lasting about three years. In the first, the aging monk adopted a diet consisting solely of seeds, nuts, and roots gathered near the monastery. He paired this with rigid physical exercises to strip his body fat to the absolute minimum. After a thousand days of this, he transitioned to a diet of nothing but pine bark and roots. By the end of the second thousand-day cycle, the monk likely resembled a walking skeleton.

Finally, daily doses of Urushi tea were added to this horrific regimen.

Urushi is the name of both the tree (Toxicodendron vernicifluum) and the lacquer derived from it, which is still used to create exquisite Japanese lacquerware. The substance is beautiful on wood and paper, but lethal to most humans—and, crucially, to the bacteria, maggots, and other agents of human compost.

The Urushi tree. Resin drainage cuts are visible on the trunk.

The tea induced vomiting, nausea, and profuse sweating, but its primary purpose was to saturate the body's tissues with toxins in preparation for the end.

In the final stage, the semi-preserved monk entered a tiny stone chamber, just large enough to sit in the lotus position. A bell connected to the outside allowed him to signal that he was still alive. When the bell fell silent, the chamber was sealed for several years. Only then would the community check if the process had succeeded. A monk who remained in the lotus position without rotting was immediately elevated to the rank of Buddha. While thousands likely attempted this, only a few achieved a state suitable for preservation. Laboratory tests on these successful practitioners show that even soft facial organs remained intact, thoroughly infused with toxic Urushi resin.

Japanese lacquerware.

One might be shocked by this deliberate, slow-motion suicide, and wonder what it has to do with the teachings of Shakyamuni Buddha, who rejected asceticism in favor of the Middle Way. Yet there is something arresting about a person choosing such an extreme path at the end of their life—confronting death daily through an agonizing physical transformation that required mental discipline of unimaginable intensity.

A Japanese lacquer monk.

The monk Shinnyokai-Shonin (1687-1783).