After the fall of the Roman Empire at the beginning of the first century, alchemical ideas moved into the Islamic world where they were preserved and developed for thousands of years. Though Muslim alchemists documented a lot of research during this time, it was generally ignored by their European counterparts until much, much later. Alchemy first appeared in Europe during the eighth century when Islamic alchemists brought it to Spain but; it would not become popular or heavily practiced until the beginning of the Renaissance in the late 12th century. Once alchemists of the time were able to write down and recreate their findings, the spells and rituals of old began to seem more and more like scientific experiments.
Jabir Ibn Hayyan or Geber as he was known in the west was a chemist who lived in Iran from 721 to 815. He is attributed to the development of the Mercury/Sulfur theory. This theory states that all minerals are derived from these two substance. Mercury was seen as a watery, vapor substance and sulfur as an earthy smoke like substance. This came of the back of Aristotle's work as Mercury was the pure, mineral form of water and air while sulfur was the form of earth and fire. These elements also had many other meanings such as male (sulfur) and female (mercury), and were often viewed as one elements that had been separated, and wanted to come back together. Geber's work is often muddled in history as during the 13th and 14th centuries, a European alchemist wrote under his name. At the time, Geber was highly esteemed and it was believed that these were simply his works being translated from Arabic to Latin. Modern historians refer to this unknown author as Pseudo-Geber.
Throughout history, religion has played a major role in alchemy. It motivated alchemists to find out what god was trying to tell them and how he showed his work through nature. In Islam, they believed it was their responsibility to understand their world and alchemists spent their lives trying to attain knowledge. In Christianity, the philosophers stone was often seen as having to do with the apple of Eden. Alchemy being intertwined with religion has had diverse effects as it provided motivation for some, but brought others much scrutiny.
Roger Bacon is widely considered to be the first, real, European alchemist. He lived from 1220 to 1292 and introduced the west to Aristotelian ideas. He was ahead of his time in scientific reasoning and around 1247 he began working in one of the world's first chemistry labs. He focused on experimental science and studied distillation for medical purposes. Bacon aimed to separate pure substances from impure elements to enhance the power of their spiritual and physical properties. Like many philosophers of the time, he believed in the Islamic theory of two element (sulfur and mercury) being responsible for all substances. Through his studies he thought he could find and harness these substances. Possibly his biggest contribution was that he was first western person to properly explain the process of making gunpowder after he. Bacon was not just an alchemist though as he spent much of his life studying optics and even had ideas for flying machines that preceded Leonardo Da Vinci.
The church had supported alchemical research up to this point but in the 1317, Pope John XXII Papal Bull banned "alchemical counterfeit". The Spondent Pariter made studying alchemy very difficult and drove practitioners to secrecy. Alchemy was made further difficult when King Charles the fifth forebode anyone from practicing it without a proper permit. These, as well as many other restrictions across the world paved the path for the secret and cryptic nature of alchemical study.
Paracelsus was an alchemist who lived from (approx.) 1493-1541. One of his greatest contributions was his idea that there were three principle elements, not just two as mentioned in many Islamic works. He theorized that mercury, sulfur and salt made up all of creation. On the philosophical side or alchemy, these element in balance, were perfection. Mercury was spirit, sulfur was soul and, salt was body. As with most alchemical works of the time, Paracelsus aimed to find a balance in these three substances. He and his followers created a new alchemical philosophy which rivaled what was being taught in schools at the time. Another of his greatest contributions to science was his theory of germs. He theorized that not all illness was a problem within the body but that it was because of external forces creating an imbalance of minerals in the body. This lead to him often being referred to as the founder of toxicology.
John Dee was a rather well known alchemist who lived from 1527 to 1609 (approx). He was regarded as one of the most learned men of his time and was known for being a sorcerer. He spent most of his life studying a wide range of sciences and the occult. Dee acted as an advisory to Queen Elizabeth the 1st and acted as her personal scientist, magician and spymaster. He gained a reputation of of mystery and power which he used to distract and deceive the people he needed to for his work. One of his alchemical contributions was his work on the "Enochian Texts". These texts allegedly allowed him to communicate with angels through certain rituals. No one else was ever able to reproduce his results which is often attributed to the precision and complexity of his experiments.
An extremely important element of alchemy is how it blurred the line between science and mysticism. Though by today's standards many of the "experiments" would be considered spells or rituals, the hermetic philosophies of the time were very detailed and precise. It was a general rule that you needed to write down your findings and be able to reproduce them. Due to the cryptic writing style of alchemy though, even well published findings were often impossible to reproduce without knowing the exact, proper translation.
The most important thing to note about Simon Foreman is that he was not a very good scientist. He was born in 1552 in London and lived until 1611. With a high literacy rate and a lot of practical knowledge for a man in his time, he managed to convince many people of the legitimacy of alchemy. In just ten years (1590-1600) he wrote over fifteen thousand pages on alchemy. His work documented his life as an alchemist, astrologer and magician. As an astrologer, he would tell people what ailed them and make medicine to cure them. Foreman allegedly produced the elixir of life among many other potions that may have been magical, though were likely herbal in nature. He believed in a much more Paracelsian approach to alchemy and was very hands on. Despite using his "astrological knowledge" to find people's sickness and cure them with his "alchemical talents", Simon Foreman refused to work for a legitimate apothecary as, in the end, he was not a real physician.
One problem many legitimate alchemists and scientists faced were Puffers. Puffers were fake alchemists who didn't write down their findings and and had little to know real knowledge. They made people believe alchemy wasn't real and claimed they could turn things into gold. Though some of these "experiments" may have resulted in gold, almost all were just tricks. Because there was no real way to test for gold, if something was yellow, malleable and heavy, it was as good as gold. Puffers often had enough successful results and legitimacy that they could continue scamming people which is why these fake alchemists lasted so long. The most famous of these Puffers is Nicholas Flamel. He earned a huge reputation in renaissance Europe and many texts were "attributed" to him. His life became that of legend as he was reputed to have achieved the two main goals of alchemy. He allegedly made the philosophers stone which could turn anything to gold and made him and his wife immortal. Though there is no legitimacy to him at all, Nicholas Flamel is one of the most well known alchemists in history.
Robert Boyle was and Alchemist and Chemist in Europe during the mid 1600's. He was very different from many traditional alchemists as he was mostly focused on the scientific parts. He found the alchemical process fascinating but disliked the secretive nature of recording his findings. Boyle also wrote a book titled "The Skeptical Chymist" in which he explained his model of the atom and rejected both Aristotle four element and Paracelsus's three element theories. His largest contribution to alchemical study was when he found a way to dissolve gold. This "anti-elixir" caused Boyles passive obsession with alchemy to grow as he thought maybe, he could reverse the process and turn something into gold. While he did contribute greatly to the separation of alchemy into mystical and chemistry elements, he was obsessed with finding the philosopher's stone and using his "anti-elixir" to transmute base elements into gold.
As time went on and science progressed from the 16-1800's, alchemy became less and less legitimate and chemistry bean to take its own form. It always had superstition and religion surrounding it but when the renaissance era began to shake things up, this made people more skeptical. Alchemy's development was also halted because it never had a presence in universities. It was a very hands on science that was not easily taught. Because of this, doctors often worked with a surgeon to help people. Another thing that halted alchemy's development was its secretive nature. All texts were written in code so even though research was often published widely, there is no way to tell how much anyone really knew. Alchemists did this because they believed their knowledge was too powerful and that they were chosen by god to do their work. This made it so alchemists often repeated each other's work rather than developing onto it. Nowadays, none of the mystical element really amounted to anything and only the scientific elements have survived.
Sir Isaac Newton was a famous scientist, mathematician and yes, alchemist. Though it is not very common knowledge, Newton wrote more on alchemy than he did on optics and physics combined. This is unknown to most of the public because after his death in 1727, the Royal Society (a UK based science organization) deemed his work unfit to be printed and kept most of it a secret. Newton worried that natural philosophy at the time was pushing out the belief in the divine. He decided that he wanted to decode the texts of alchemists before him and by the end of his life, he believed he knew what it had meant. His ideas in alchemy may have influenced many of his theories in motion and gravity as around the time he came to understand alchemy, he created his theory of gravity. Newton was also heavily influenced by the works of Robert Boyle, the aforementioned chemist and alchemist.