Paracelsus attributes incorruptibility to a special virtue or agent named ‘balsam.’ This was something like a natural elixir, by means of which the body was kept alive or, if dead, incorruptible.
Jung identifies balsam as Paracelsus’s term for the invisible preservative principle animating living matter and guaranteeing incorruptibility — a proto-psychological concept of vital integration.
, Alchemical Studies, 1967thesis