What do Mercury and Sulfur represent in Alchemy?

Answer from the V.M. Samael Aun Weor.

Mercury (I already told you, don't forget it, and I repeat it to you) is the Metallic Soul of sexual secretions, both in men and women.

Sulfur is Fire; the Fire that must be released from its prisons to fertilize Mercury and mix with Salt.

The works of the NINTH SPHERE are usually very delicate. Salt, Sulfur and Mercury, together, constitute the AZOE, or better said, the VITRIOLO: "Visita Interiora Terrae Rectificando Invenies Occultum Lapidem"; visit the interior of the Earth, that by rectifying you will find the Hidden Stone, that is, the Philosopher's Stone.

Samael Aun Weor. Excerpt of the book: Gnostic Revelations on Baptism.

Answer from the Magazine "The Wisdom of the Being".

In alchemy these creative energies are called the philosophical mercury, represented by the woman, the flask and the water. If there is the water element, fire must also be represented by the masculine element (the Father) and his face is with fire, in alchemy this element is represented by sulfur.

It is very interesting that the masculine principle has at its least the bellows, to fan the fire, since it is the active principle of creation and tells us to learn to use the science of breath to control and fan the fire at work.

The Wisdom of Being Magazine 96, Chapter: "The Fifth Key of Basil Valentin."