Coagulatio constitutes one of the major alchemical operations, and is another of the procedures tied to one of the four classical elements. Just as calcinatio is the operation of the element fire, solutio the water operation, and sublimatio the operation pertaining to air, so coagulatio belongs to the symbolism of the element earth.
As with all of the alchemical operations, coagulatio refers first of all to experience in the laboratory. A solid that has been dissolved in a solvent reappears when the solvent is evaporated is one example. In another case a chemical reaction may produce a new compound that is solid for example, the coagulation of egg white when it is heated.
Beyond the alchemist’s laboratory, coagulatio is the process that turns something into earth. “Earth” is thus one of the synonyms for the coagulatio. It is heavy and permanent, of fixed position and shape. It doesn’t disappear into the air by volatilizing nor pliantly adapt itself to the shape of any container as does water. Its form and location are fixed. For me the ultimate image of coagulatio is lava slowly congealing into solid rock. Eventually this barren rock breaks down into rich fertile soil but it is still earth.
One alchemical text mentions three agents of coagulatio: magnesia, lead, and sulphur. Magnesia had a different meaning in alchemy than it does to modern people. It was a general term referring to various crude metallic ores or impure mixtures. Psychologically this could refer to the union of the transpersonal spirit with ordinary human reality
The next agent of coagulatio mentioned is lead. Lead is heavy, dull, and burdensome. It is associated with the planet Saturn, which carries the qualities of depression, melancholy, and frustrating limitation. Thus, free, autonomous spirit must be yoked with heavy reality and the limitations of personal particularity. In analytic practice this linkage with lead is often accomplished when the individual takes personal responsibility for fleeting fantasies and ideas by expressing them to the analyst or to another person. The difference between an idea thought and an idea spoken is the difference between mercury and lead.
The third coagulating agent mentioned is sulphur. Its yellow color and inflammability associate it with the sun. On the other hand, its vapors stink and blacken most metals so that brimstone is a characteristic feature of hell. Jung summaries his masterful discussion of the symbolism of sulphur in “Mysterium Coniunctionis ( CW14: par. 151 ) and says “As the corrupter it has affinity with the devil, while on the other hand it appears as a parallel of Christ” ( CW14: par. 153 ). Thus, if part of the meaning of sulphur is desirousness the striving for power and pleasure we reach the conclusion that desire coagulates.
Thus, for a psychic content to become earth means that it has been solidified into form that is, it becomes attached to an ego. In conclusion, the alchemical operation of coagulatio, together with the accompanying imagery, presents a symbol system expressing the archetypal process of ego formation. When the ego is approaching the coagulatio of the psyche in its totality this symbolism of ego development becomes identical with that of individuation.
Myths tell us coagulatio is promoted by action (diving, churning, whirling motion). They correspond to what Faust learned from the Spirit of Mephistopheles: “In the beginning was the deed” ( Goethe, Faust, pt. 1, line 1237 ). Psychologically this means that activity and psychic movement promote ego development.
In addition coagulatio is linked with birth and physical manifestation as the product of desire. Just as alchemists used the terms “body” and “flesh” refer to coagulatio, so food imagery belongs to the same symbolism. Desire for the forbidden fruit bought Adam and Eve into the physical world from paradise. Desire spurs the action that leads to coagulatio and desire is often aroused by sweetness..
According to the alchemist Dorn’s recipe for joining the spirit (unio mentalis) with the body, one of the required agents is honey. Honey, because of its preservative qualities, was considered by the ancients to be a medicine of immortality and had a Eucharistic use in some early Christian communities. Honey as the supreme example of sweetness is an agent of coagulatio. Paracelsus says that “the prime matter of honey is the sweetness of the earth which resides in naturally growing things.” And again, honey “is the prime materialized matter, for honey and wax are one.”