Quæ sunt in superis hac inferioribus insunt; Quod monstrat coelum, id terra frequenter habet. Ignis, Aqua et Fluitans, due sunt contraria; Felix talia si jungis, sit tibi scire satis.
ALCHEMY is that science which results from a knowledge of God, Nature, and Man. A perfect knowledge of either of them cannot be obtained without the knowledge of the other two, for these three are one and inseparable.
Alchemy is not merely an intellectual, but a spiritual science; because that which belongs to the spirit can only be spiritually known. Nevertheless, it is a science dealing with material things, for spirit and matter are only two opposite manifestations or "poles" of the eternal one.
Alchemy is an art, and as every art requires an artist to exercise it, likewise this divine science and art can be practised only by those who are in possession of the divine power necessary for that purpose. It is true that the external manipulations required for the production of certain alchemical preparations may, like an ordinary chemical process, be taught to anybody capable of reasoning; but the results which he would accomplish would be without life, for only he in whom the true life has awakened can awaken it from its sleep in the prima materia, and cause visible forms to grow from the Chaos of nature.
Alchemy in its highest aspects deals with the spiritual regeneration of man, and teaches how a god may be made out of a human being or, to express it more correctly, how to establish the conditions necessary for the development of divine powers in man, so that a human being may become a god by the power of God, in the same sense as a seed becomes a plant by the aid of the four elements, and the action of the invisible fifth.
Alchemy in its more material aspect teaches how minerals, metals, plants, and animals, and men, may be generated, or made to grow from their "seeds"; or, in other words, how that generation, which is accomplished during long periods of time in the due course of the action of natural laws, may be accomplished in a comparatively very short time, if these natural laws are guided and supplied with material, by the spiritual knowledge of man. There is no doubt in my mind that gold can be made to grow by alchemical means; but it requires an Alchemist to make the experiment succeed, and he who is attracted by the power of gold will not obtain possession of the spiritual power necessary to practise that art.
It is not the object of these pages to furnish proof to the sceptic that Alchemy is a truth, nor to furnish arguments on the strength of which the incredulous may become persuaded to believe in its possibility. To believe in a thing of which one has no knowledge would be of little benefit; but those who have some spiritual knowledge of Alchemy, perhaps having studied it in some former incarnation, may receive some benefit from a perusal of this chapter, as it may serve to bring that which they already spiritually know to the understanding of their mind. *
* There are two kinds of knowledge in man, namely, that which belongs to his spirit (Budhi), and that which belongs to his mind (Manas). The former is, so to say, the quintessence of what man has learned in previous incarnations; the latter is that which he has learned in his present life. [Essence vs Personality, in Gurdjieff's terminology.] If he were to succeed to rise up in his mind to the sphere of his spirit, to unite his Budhi with his Manas; then would the mind share the knowledge which the spirit possesses.
It is a mistake to confound Alchemy with Chemistry. Modern Chemistry is a science which deals merely with the external forms in which the element of matter is manifesting itself. It never produces anything new. We may mix and compound and decompose two or more chemical bodies an unlimited number of times, and cause them to appear under various different forms, but at the end we will have no augmentation of substance, nor anything more than the combinations of the substances that have been employed at the beginning.
Alchemy does not mix or compound anything, it causes that which already exists in a latent state to become active and grow. Alchemy is, therefore, more comparable to botany or agriculture than to Chemistry; and, in fact, the growth of a plant, a tree, or an animal is an alchemical process going on in the alchemical laboratory of nature, and performed by the great Alchemist, the power of God acting in nature.
The nature of Alchemy is clearly explained by Johannes Tritheim,  who says:—
"God is an essential and hidden fire in all things, and especially in man. That fire generates all things. It has generated them, and will generate them in the future, and that which is generated is the true divine light in all eternity. God is a fire; but no fire can burn, and no light appear within nature without the addition of air to cause the combustion, and likewise the Holy Spirit in you must act as a divine 'air' or breath, coming out of the divine fire and breathing upon the fire within the soul, so that the light will appear; for the light must be nourished by the fire, and this light is love and gladness and joy within the eternal deity. This light is Jesus, having emanated from eternity from Jehovah. He who has this light not within himself is in the fire without light; but if the light is in him, then is the Christ in him, and takes form in him, and such a person will know that light as it exists in nature.
"All things such as we see are in their interior fire and light, wherein is hidden the essence of the spirit. All things are a trinity of fire, light, and air. In other words, 'Spirit,' the 'father,' is a divine superessential light; the 'son,' the light having become manifest; the 'holy spirit' a divine superessential air and motion. The fire resides within the heart and sends its rays through the whole body of man, causing it to live; but no light is born from the fire without the presence of the spirit of holiness." 
[2. Christian Alchemy: Christ the Stone www.alchemylab.com/christian.htm ]
To express this in other words we may say—All things are made of thought, and exist in the universal mind (the astral light), and within each is latent the will, by whose action they may become developed and their powers unfolded.
This takes place under favourable circumstances by the slow and unconscious action of the universal will acting in nature, and may be accomplished in a very short time by the aid of the conscious will of the alchemist; but before the will of a person can accomplish such wonders in external substances, his will must first become self-conscious within itself; the light that shines from the centre of his own heart, must become living and bright before it can act upon those substances with which the Alchemist deals.
He in whom this divine light of the Christ (the Atma) has not awakened to life, is virtually asleep in the spirit, and can act upon spiritual things no more than a man can deal with material substances while he sleeps; but this fact will hardly be acknowledged or comprehended by the superficial scientist and rationalist, who imagine themselves to be fully awake, and therefore the secrets of alchemy are an inexplicable mystery to them, which can be disposed of in no other way than by being denied or laughed away.
Alchemy was known at the most ancient times. It was no secret to the initiates among the ancient Brahmins and the Egyptians; and the Bible, if read in the light of the Cabala, will be found to be the description of an alchemical process.
The Aleph א represent three fiery flames, nevertheless, it is only one letter. In Magic it means AOH, the Father, the one from which all the rest take their origin, the Alpha and likewise the Omega, the beginning and also the end. As the air causes the fire to burn and to emit a light, likewise the Holy Spirit (without whose presence nothing can be accomplished) nourishing the divine fire with the soul, causes the living light of the Christ to become manifest. This is also indicated in the three first letters of the word פדאשיח, for the פ means "Ben," the son; the א AOH, the father; and ד means "Ruach," or spirit. This, then, is a trinity of father, son, and spirit, and its quality is indicated by the following syllable איח, indicating the true generation, for the ש is the letter symbolizing the fire, and the י the light. The pronunciation of the former is like the hissing of the flame, but the latter issues mildly from the fire, as it is likewise born mildly and humbly within the human soul while the כ symbolizes the spirit and the power of the outspoken word. 
[3. Any help with translation to English would be welcome.]
The "Song of Solomon," in the Old Testament, is a description of the processes of alchemy. In this Song the Subjectum is described in Cant, i., 5; the Lilium artis in C. ii., 1; the Preparation and Purification in C. ii., 4; the Fire in C. ii., 7, and C. iv., 16; the Putrefaction in C. iii., 1; Sublimation and Distillation in C. iii., 6; Coagulation and Change of Colours, C. v., 9 to 14; Fixation, C. ii, 12, and C. viii, 4; Multiplication, C. vi., 7; Augmentation and Projection, C. viii. 8, etc., etc.
With all this, it must not be supposed that the practice of Alchemy consists merely in the exercise of the will and the imagination; or that the products obtained are merely imaginary and intangible or invisible to mortal eyes. On the contrary, no alchemical processes can be accomplished without the presence of visible and tangible matter, as it is so to say a spiritualizing of "matter."
There is no transformation of "matter" into "spirit," as some people believe, for each of the seven principles of eternal nature is unchangeable, and remains for ever in its own centre, in the same sense as darkness cannot be turned into light, although a light may be kindled within the darkness, in consequence of which the darkness will disappear. Likewise within each material form there sleeps the divine spirit, the light, which may become awakened to life and activity, and illuminate the body and cause it to live and to grow. Of the qualities of the powers of that light, or even of its existence, modern chemistry has no knowledge and no names to describe it; but they are described under various names in the Bible, and in the still older religious books of the East.
There is a visible substance and an invisible one; a tangible water and one that is beyond the reach of perception by the physical senses; a visible fire and an invisible magic fire; neither can either of these accomplish anything without the other, for in the practice of Alchemy, as in the regeneration of man, that which is above must be made to penetrate that which is below, so that the lower may enterinto a higher state of existence.
The "Prima Materia"
If we wish to know nature we must learn to know God, and God cannot be known without a knowledge of one's own divine self. The spiritual substance of which external visible nature is an imperfect expression and manifestation, has been called "Prima Materia"; it is the material for the formation of a new heaven and a new earth. It is like "water," or a "crystalline ocean," if compared with our grossly material earth; it is at once fire, water, air, and earth, corporeal in its essence, and nevertheless, incorporeal relatively to our physical forms.
In it as the "Chaos," are contained the germs, or seeds, or "potencies" of all things that ever existed, and of all that ever will exist in the future. It is the soul, or corpus of nature, and by means of the magic fire, it may be extricated from all substances, and be rendered corporeal and visible. It is a unity, and nevertheless a trinity, according to its aspects as Sulphur, Mercury, and Salt.  These three are distinct qualities characterising the spirit of light, and nevertheless they are nothing different from the essence of the light, and this light is eternal nature, or the soul of the world.
[4. See Hartmann's Life of Paracelsus, published 1887, chapter 1: 'Thus,
for instance, when [Paracelsus] speaks of "Sulphur", he, like other Alchemists of
his times, refers to a certain active energy or form of the will, for which even
modern science has not yet invented a name, and for which the term "Sulphur" is
a symbol, in the same sense as "Mercury" is a symbol for intelligence, "Salt " for
substance, "Venus" for love, and so forth.' selfdefinition.org/magic/
This primordial matter contains the powers that go to form minerals and metals, vegetables and animals, and everything that breathes; all forms are hidden within its depths, and it is therefore, the true principium or beginning of all things. It is the play and battle ground for all the astral influences that come from the stars and the birthplace of the beings that inhabit the astral plane, not less than of those that are born into the (to us) visible world. It is the womb of eternal nature from which everything that exists is born by the power of the spirit acting within. From its fertile soil are produced good and evil fruits, wholesome and noxious plants, harmless and poisonous animals, for God is no distinguisher of persons, or favouring any particular individual; each receives its share of life, and will, according to its capacity to receive, and each becomes ultimately that which its character destines it to be.
The "Spiritus Universialis"
"Without which no alchemical experiment will succeed".
Johannes Tritheim [see ref. above] an abbot and alchemist, whose writings are plainer and more comprehensible than any other alchemical book, says:
"All things have been made by the power of the divine word, which is the divine spirit or breath that emanated from the divine fountain in the beginning. This breath is the spirit or soul of the world, and is called the "spiritus mundi." It was at first like air, and contracted into a fog or nebular substance, and afterwards became "water" (Akasa). This "water" was at first all spirit and life, because it was permeated by and made alive by the spirit. It was dark in the depths; but through the outspoken word the light became generated therein, and then the darkness was illumined by the light, and the "soul of the world" (the astral light) had its beginning. This spiritual light, which we call "Nature," or the soul of the world, is a spiritual body, which, by means of Alchemy, can be made tangible and visible; but as it exists in an invisible state, therefore is it called "spirit."
"This is an universal and living fluid diffused throughout the All of Nature, and which pervades all beings. It is the most subtle of all substances, the most powerful on account of its inherent qualities, penetrating all bodies, and causing the forms in which it is active to live. By its action it frees the forms of all imperfections, and renders the impure pure, the imperfect perfect, and causes that which is mortal to become immortal by becoming fixed therein."
"This essence of spirit has emanated from the centre in the beginning, and is incorporated into the substance of which the world is formed. It is the Salt of the Earth, and without its presence the grass would not grow, nor the fields be green; and the more this essence is condensed, concentrated, and coagulated in the forms, the more enduring will they become.
"This substance is the most subtle of all things, incorruptible, unchangeable in its essence, pervading the infinity of space. The sun and the planets are merely condensed states of this universal principle, and they distribute their abundance from their throbbing hearts, and send them into the forms of the lower worlds and into all beings, acting through their own centres, and leading the forms higher up on the road to perfection. The forms in which this living principle becomes fixed become perfect and permanent, so that they will neither rust nor decay, nor be changed on being exposed to the air; neither can such forms be dissolved by water, nor be destroyed by fire, nor eaten up by the elements of the earth.
"This spirit can be obtained in the same manner in which it is communicated to the earth by the stars; and this takes place by means of water, which serves as its vehicle. It is not the Philosopher's Stone, but the latter may be prepared of it by causing that which is volatile to become fixed.
"I admonish you to pay strict attention to the boiling of the water, and not to allow your minds to be disturbed by things of minor importance. Boil it slowly, and let it putrefy until it attains the proper colour, for in the water of Life is contained the germ of wisdom. By the art of boiling the water will become transformed into earth. This earth is to be changed into a pure crystalline fluid, from which an excellent red fire is produced; but this water and fire, grown together into one essence, produces the great Panacea, composed of meekness and strength: the lamb and the lion in one."
The Secret Fire
In H. P. Blavatsky's book "The Voice of the Silence,"  the secret fire of the Alchemists is described as "Kundalini," the "serpentine," or annular working power in the body of the ascetic. "It is an electric fiery occult or Fohatic power, the great pristine force which underlies all organic and inorganic matter"; and in another place the author says: "It is an electro-spiritual force, a creative power which, when aroused into action, can as easily kill as it can create."
This point is the reason why the secrets of Alchemy are rot divulged to the curious, and why only those who have gained the power to control their own self will be told how that power can be aroused in man.
In regard to this "secret fire," the Rosicrucians say:
The potentialities in nature are aroused by the action of the secret fire, assisted by the elementary fire. The secret fire is invisible, and is contained within all things. It is the most potential and powerful fire, with which the external visible fire cannot be compared. It is the fire with which Moses burned the golden calf, and that which Jeremiah hid away, and which seventy years after was found by the knowing ones, but which, by that time had become a thick water. (2 Maccab. I. and II.) 
Without the possession of this magic fire, no alchemical process can be accomplished, and therefore it is recommended in the "Secret Symbols of the Rosicrucians," [7, 8] that the student of Alchemy should above all seek for the fire.
[7. Abbreviated version: Link opens a PDF, 16 pages, 158K: selfdefinition.org/magic/Secret-Symbols-of-the-Rosicrucians.pdf ]
[8. Full version: www.rosicrucian.org/secret-symbols-of-the-rosicrucians ]
Axiomata Hermetica – 43 Axioms of Alchemy
1. Whatever may be accomplished by a simple method should not be attempted by a complicated one.
There is only one Truth, whose existence requires no proof, because it is itself proof enough to those who are capable of perceiving it. Why should we enter into complexness to seek for that which is simple? The sages say: "Ignis et Azoth tibi sufficiunt."  The body is already in your possession. All that you require is the fire and the air.
[7. Fire and Azoth are sufficient. en.wikipedia.org/wiki/Azoth ]
2. No substance can be made perfect without long suffering.
Great is the error of those who imagine that the Philosopher's Stone can be hardened without being first dissolved; their time and labour is wasted.
3. Nature must be aided by art whenever she is deficient in power.
Art may be the handmaid of nature, but cannot supplant her mistress. Art without nature is always unnatural. Nature without art is not always perfect.
4. Nature cannot be amended except in her own self.
The nature of a tree cannot be changed by trimming the branches or by the addition of ornaments; it can be improved only by improving the soil upon which it grows, or by grafting.
5. Nature enjoys, comprehends, and overcomes nature.
There is no other actual knowledge than the knowledge of self. Every being can only truly realize its own existence, but not that of any element entirely foreign to it.
6. He who does not know motion does not know nature.
Nature is the product of emotion [sic]. At the moment in which eternal motion should cease, all nature would cease to exist. He who does not know the motions that are taking place in his body is a stranger in his own house.
7. Whatever produces the same effect as is produced by a compound is similar to the latter.
The One is greater than all the rest of the numbers, for from it an infinite variety of mathematical magnitudes may be evolved; but no change is possible without the all-pervading presence of the One, whose qualities are manifest in its manifestations.
8. No one can pass from one extreme to another except through a medium.
An animal cannot become divine before it becomes human. That which is unnatural must become natural before its nature can become spiritual.
9. Metals cannot be changed into other metals without having been first reduced to prima materia.
The self-will, opposed to the divine, must cease before the divine Will can enter into the heart. We must become unsophisticated, like children; before the word of wisdom can speak in our mind.
10. The unripe must be assisted by the ripe.
Thus fermentation will be induced. The law of Induction rules in all departments of nature.
11. In the Calcination, the Corpus is not reduced but augmented, in quantity.
True asceticism consists in giving up that which one does not want after having received something better.
12. In Alchemy nothing can bear fruit without having first been mortified.
The light cannot shine through matter unless the matter has become sufficiently refined to allow the passage of the rays.
13. That which kills, produces life; that which causes death, causes resurrection; that which destroys, creates.
Nothing comes out of nothing. The creation of a new form is conditioned by the destruction (transformation) of the old one.
14. Everything containing a seed may be augmented, but not without the assistance of nature.
It is only through the seed that the fruit bearing more seeds comes into existence.
15. Each thing is multiplied and augmented by means of a male and female principle.
Matter produces nothing unless penetrated by power. Nature creates nothing unless impregnated by Spirit. Thought remains unproductive unless rendered active by Will.
16. The virtue of each seed is to unite itself with each thing belonging to its own kingdom.
Each thing in nature is attracted by its own nature represented in other things. Colours and sounds of a similar nature form harmonious units, substances that are related with each other can be combined, animals of the same genus associate with each other, and spiritual powers unite with their own kindred germs.
17. A pure womb gives birth to a pure fruit.
Only in the innermost sanctuary of the soul will the mystery of the spirit be revealed.
18. Fire and heat can only be produced by motion.
Stagnation is death. The stone thrown into the water forms progressively radiating circles, which are produced by motion. The soul that cannot be moved cannot be elevated, and becomes petrified.
19. The whole method is begun and finished by only ONE method: THE BOILING.
The great Arcanum is a celestial spirit, descending from the sun, the moon, and the stars, and which is brought into perfection in the saturnine object by continuous boiling until it attains the state of sublimation and power necessary to transform the base metals into gold. This operation is performed by the hermetic fire. The separation of the subtle from the gross must be done carefully, adding continually water; for the more earthly the materials are, the more must they be diluted and made to move. Continue this process until the separated soul is reunited with the body.
20. The entire process is accomplished through nothing else but Water.
It is the same Water over which the Spirit of God moved in the beginning, when darkness was upon the face of the deep.
21. Each thing comes from and out of that into which it will be resolved again.
That which is earthy comes from the earth; that which belongs to the stars is obtained from the stars; that which is spiritual comes from the Spirit, and returns to God.
22. Where the true principles are absent, the results will be imperfect.
Mere imitations cannot produce genuine results. Merely imaginary love, wisdom, and power can only be effective in the realm of illusions.
23. Art begins where nature ceases to act.
Art accomplishes by means of nature that which nature is unable to accomplish if unaided by art.
24. The hermetic art is not attained by great variety of methods, the LAPIS is only one.
There is only one eternal, unchangeable truth. It may appear under many different aspects; but in that case it is not the truth that changes: it is we who change our modes of conceiving of it.
25. The substance of which the ARCANUM is prepared should be pure, indestructible, and incombustible.
It should be pure of grossly material elements, indestructible by doubt, and incapable of being burned up in the fire of passion.
26. Do not seek for the seed of the PHILOSOPHER'S STONE in the Elements.
Only at the Centre of the fruit is that seed to be found.
27. The substance of the Philosopher's Stone is mercurial.
Those that are wise are seeking for it in the mercury; the fool seeks to create it out of his own empty brain.
28. The seed of the metals is in the metals, and the metals are born of themselves.
The growth of the metals is very slow; but it may be hastened by the addition of Patience.
29. Use only perfect metals.
Crude mercury, such as is usually found in European countries, is perfectly useless for this work. Worldly wisdom is foolishness in the eyes of the Lord.
30. That which is hard and thick must be made subtle and thin by calcination.
This is a very painful and tedious process, because it is necessary to remove even the root of evil, and this causes the heart to bleed, and tortured nature to cry out.
31. The foundation of this art is to reduce the CORPORA into ARGENTUM VIVUM.
This is the Solutio Sulphuris Sapientium in Mercurio. A science without life is, a dead science; an intellect without spirituality is only a false and borrowed light.
32. In the solution the solvent and the dissolved must remain together.
Fire and water must be made to combine. Thought and love must remain for ever united.
33. If the seed is not treated by warmth and moisture, it will be useless.
Coldness contracts and dryness hardens the heart, but the fire of divine love expands it, and the water of thought dissolves the residua.
34. The earth produces no fruit unless moistened repeatedly.
No revelation takes place in the darkness except through the light.
35. The moistening takes place by water, with which it has the closest affinity.
The body itself is a product of thought, and has therefore the closest affinity with the mind.
36. Everything dry naturally tends to attract the moisture which it requires to become complete in its constitution.
The One, from which all things are produced, is perfect; and therefore all things contain within themselves the tendency and possibility for perfection.
37. A seed is useless and impotent unless it is put in its appropriate matrix.
A soul cannot develop and progress without an appropriate body, because it is the physical body that furnishes the material for its development.
38. Active heat produces in that which is moist blackness; in that which is dry, whiteness; and in that which is white, a yellow colour.
First comes mortification, then calcination, and afterwards the golden glow produced by the light of the sacred fire illuminating the purified soul.
39. The fire must be moderate, uninterrupted, slow, equal, moist, warm, white, light, all-embracing, enclosed, penetrating, living, inexhaustible, and the one used by nature.
It is the fire that descends from heaven to bless all mankind.
40. All operations must take place in only one vessel and without removing it from the fire.
The substance used for the preparation of the Philosopher's Stone should be collected only in one place and not be dispersed in many places. If the gold has once lost its brightness, it is difficult to restore it.
41. The vessel should be well closed, so that the water may not run out of it, or the air escape; it ought to be hermetically sealed, because if the spirit were to find a place to escape, the power would be lost; and furthermore it should be well closed, so that nothing foreign and impure can enter and become mixed with it.
There should always be put at the door of the laboratory a sentinel with a flaming sword to examine all visitors, and to reject those that are not worthy to be admitted.
42. Do not open the vessel until the moistening is completed.
If the vessel is prematurely opened, most of the labour is lost.
43. The more the Lapis is nursed and nourished, the more will it increase.
Divine wisdom is inexhaustible; the limitation exists only in the capacity of the form to receive it.
[ end of chapter ]