"Representation of Hermes Trismegistus on the ornamental tiling of the cathedral of Siena. This image is reproduced in several manuals on alchemy. The following inscription can be read on the tablet carried by Hermes:
DEUS OMNIUM CREATOR SECUM DEUM FECIT VISIBILEM ET HUNC FECIT PRIMUM ET SOLUM QUO OBLECTATUS EST VALDE AMAVIT PROPRIUM FILIM QUI APPELLATUR SANCTUM VERBUM
Which means: "The Lord and Creator of all things, whom we have the right to call God, since he made the second God visible and sensible... Since, therefore, he made him first, and alone, and one only, he appeared to him beautiful, and most full of all good things; and he hallowed him and altogether loved him as his own Son."
This representation of Hermes Trismegistus attributed with such a spiritual authority, within a very Christian building, has spawned numerous articles... It illustrates the mysterious place occupied by alchemy in western history."

The word 'alchemy' comes from the Arab al-kimiya, the meaning of which is still the subject of much debate. Nevertheless, one important point should be made: it would appear that whatever the language, the word 'alchemy' refers to the Sun, its mysteries and its originality. Similarly, the Hebraic equivalent of kimiya is Chemesh and the Turkish noun 'chems' also means sun. We can therefore talk about a whole set of esoteric theories related to the sun.

Although the oldest known follower to date was Chinese, so-called Alexandrian alchemy originated in Egypt during the 3rd century BC, coinciding with the advent of the Hellenistic period in the Mediterranean area. Spurred on by Alexander the Great, the Greeks invaded Egypt and imposed their culture. That is when the god Thot, representing writing and knowledge, was compared to the Greek Hermes. Over the centuries, Egypt became the ideal place for multiple ideas and religions, and welcomed Pagans, Jews, Christians and all mystical and hermetic trends. The Gnostic idea then came about, according to which the material is fundamentally bad and redemption can only be achieved by dissociating it from the spiritual.

Egypt fell under the Roman influence as from the 4th century, and the alchemists were hunted down on account of their worrying theories. The possibility of producing gold had the potential of inciting the anti-hegemonic movements. All manuscripts with alchemical connotations were destroyed. Even so, the science spread to the east of the Mediterranean, in Byzantium and Syria in particular.

In the 7th century, the Arabs conquered the Near East and integrated the culture of the countries that fell under their supremacy. Alchemical texts were translated and represented a major centre of interest for science enthusiasts. They brought a spiritual dimension to the discipline at the same time as devising new theories, including the one relating to sulphur and mercury.

Alchemy gradually spread to the western Christian world at the beginning of the middle ages. The texts were transcribed in Latin by monks, thereby marking the point at which the science's spiritual character was at its height, subsequently becoming a quest, or a search for knowledge. The idea of investigation particularly appealed to the novices of the west. Although its ideas sometimes appeared to be in conflict with Christianity, this practice was never compared to sorcery and was also studied by members of the Catholic school. Alchemy as a science became indissociable from the spiritual quest and the idea of human perfection. That is why most medieval alchemists turned into pilgrims, travelling throughout Europe to meet up with the day's scientists and look for clues that might lead them to the Philosopher's Stone.

Hermetic literature, stemming from Byzantium, multiplied during the Renaissance. However, alchemy progressively lost its spiritual character in favour of actual sciences, such as medicine and physics. The strictly mystical approach still continued to appeal to such occult movements as the Rosicrucians and later the Freemasons.

The 17th century represented a prolific period for the alchemists, which went hand in hand with the rediscovery of Antiquity. The number of hermetic texts and works of art increased, coinciding with the beginning of a rationalist movement. Alchemy was deemed to have an excessive magic bias, even by its peers. The next century was marked by the advent of the pre-industrial era, and chemistry won the occult sciences over to its cause. The 19th century even rejected the transformation of metals, and merely focused on the combination of bodies.

A few alchemists have survived to the present day, in search of the Philosopher's Stone, the elixir of life, the perfection of nature. In reading the ancient texts, they perpetuate a tradition that was left to one side by the progress of science. The transformation of lead into gold is a chemical absurdity, even though a few microphysicists believe that it could be done using nuclear processes, which unfortunately are too expensive for the results expected. Nevertheless, the alchemical philosophy still appeals to a number of followers throughout the world.