Philosophers Stone
This Awareness indicates that the First Matter for alchemist normally referred to as water, is that element known as urine.
The urine or First Matter, is sometimes described as Mercury and Sulfur; mercury because it flows in a liquid form, and sulfur because of the sulfur content in urine. [Philosophers Stone]

Jacob Boehme
"The word Sul means and is the soul of a thing; for in the word Sulphur it is the oil or the light, which is born from the syllable Phur. It is the beauty or goodness of a thing; its love or best beloved. In a creature it is the intelligence and sense, and it is the spirit born from the syllable Phur. The word or syllable Phur is Prima Materia, entering into the third principle within itself, the Macrocosm wherefrom the elemental (terrestrial) kingdom or essence is born; but in the first principle it is the essence of the innermost generation, wherefrom God the Father from eternity gives birth to his Son. In man it is also the light born from the sidereal spirit within the other centre in the Microcosm, but in the Spiraculum it is a soul-spirit in the inner centre. It is the light of God, which alone possesses that soul which is in the love of God, for it is kindled and breathed upon by the Holy Spirit." (Three Principles, ii. 7.)
"Sal is Prima Materia, astringency. In the strong astringency arises the bitterness; for in the powerful attraction arises the uneasiness of the spirit. For instance, if a person becomes angry, his spirit attracts that which causes him to become embittered and trembling; and if he does not resist and put it down, then the fire of wrath becomes kindled in him, so as to make him burn in malice. Then in his mind and soul this becomes substantial and a being." (Three Principles, i. 9.)
"Mercury, an astringent bitter fire—sulphur—water; the most terrible of all states; but you must not imagine it to be a Materia or a tangible thing; it is spirit and the source of the first beginning of nature." (Three Principles, i. 10.)
"It comprehends all the four qualities wherein arises the life; but it has its beginning not in the centre, like Phur, but according to the fire-flash within the terror of the dark quality." (Threefold Life, ii. 42.)
"Behold, there are especially three Things in the Originality, out of which all Things are, both Spirit and Life, Motion and Comprehensibility, viz. h Sulphur, i Mercurius, and k Sal.
But you will say that these are in Nature, and not in God; which indeed is so, but Nature has its ground in God, according to the first Principle of the Father, for God calls himself also an angry zealous God; which is not so to be understood, that God is angry in himself, but in the Spirit of the Creation or Creature which kindles itself; and then God burns in the first Principle therein, and the Spirit of the Creation or Creature suffers Pain, and not God.
h) Wherein the Kindling consists.
i) The Spirit of a Substance.
k) Salt, Body, or Substantiality.
Now to speak in a creaturely way, Sulphur, Mercurius, and Sal, are understood to be thus. S U L is the Soul or the Spirit that is risen up, or in a Similitude it is God: P H U R is the Prima Materia, or first Matter out of which the Spirit is generated, but especially the 1 Harshness: Mercurius has a fourfold Form in it, viz. Harshness, Bitterness, Fire, and Water: Sal is the Child that is generated from these four, and is harsh, eager, and a Cause of the Comprehensibility.
l) Astringency or Attraction." [Three Principles, Jacob Boehme]

See Also

Alchemy
Table of the Elements - Russell Elements