Valentinus says in

Decay is the beginning of all birth… It transforms shape and essence, the forces and virtues of nature. Just as the decay of all foods in the stomach transforms them and makes them into a pulp, so it happens outside the stomach… Decay is the midwife of very great things! It causes many things to rot, that a noble fruit may be born; for it is the reversal, the death and destruction of the original essence of all natural things. It brings about the birth and rebirth of forms a thousand times improved. … And this is the highest and greatest mysterium of God, the deepest mystery and miracle that He revealed to mortal man." [[1]]

Valentinus says in "The Chariot of Antimony":

"But digestion and putrefaction are the Master Keys of the process."

To outward appearances it seems that decay begins in the stomach - but this is actually the Centre of our energy-field, or to be more precise, the Centre of the Centre - and the Navel, the Umbilicus.The stomach is the centre of digestion and therefore the seat of putrefaction.

This 'Centre' is the Hermaphrodite with Two-heads: the REBIS.

It becomes obvious that this Centre, as a Great Reconciliator of the opposites, is Mercury, that is; HERMETIC.

"The point as the centre of the quarternio of the elements is the place where Mercurius "digests and perfects."" Jung.

Mercury is therefore one of the Master Keys, connected to digestion and decay. The digestion aspect I would think is the Mercurial/Hermetic processes as great integrating fields of action - absorbed in activity. Decay, as a manifestation of the impermanence of the cycles of phenomena, is organic change, and therefore URANUS, or URANIAN, the higher octave of Mercury. The Wheel of Life proceeds with and without structure.

But decay is essentially the texture of Pluto.

Golden Mould - Frazer . .

fusion of Solar and Plutonic, gold on black . .

SOL NIGER, BLACK SUN, Jung, C.G. Mysterium Coniunctionis, p. 95.

Synonymous with CAPUT CORVI.

[1] Paracelsus, Selected Writings, Edited with an Introduction by Jolande Jacobi, Princeton University Press, 1951, Bolligen Series XXVIII, p. 143-144.