Self Mummification
Sokushinbutso were Buddhist priests or monks who caused their own death, in a way that they became mummified afterwards. This practice mostly took place in Northern Japan, where 16 to 24 mummifications where detected.
For three years, the priests will have a diet consisting only of seeds and nuts, while engaging in a thorough physical activity that removed their body fat. Then, for another three years, they ate only bark and roots, and began consuming a poisonous tea made from the liquid of the Urushi tree. This lead to vomiting and a fast loss of body liquid, and most importantly it eliminated any material that would lead to the decay of the body after death.
Finally the monk would lock himself in a stone tomb that barely fits him, with a small air tube and a bell. Every day the monk would ring the bell to let the people outside know that he is still alive. When the bell stopped ringing, the tube was removed and the tomb sealed.
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