The term “hermetically sealed” derives from the name of the Greek god Hermes, who conducted souls into the afterlife. When the Greeks learned that the Egyptians had a god Thoth, or Tehuti, who specialized in wisdom and learning, they named him Hermes Trismegistus, or “thrice greatest Hermes.” Supposedly Hermes Trismegistus was the scribe of the gods who authored the sacred hermetic works that described the material world as well as the quest for spiritual perfection. This is just what the alchemists were interested in, so they latched onto Hermes Trismegistus as their patron. The alchemists often used distillation in their attempts to change matter from one form to another, a process that required making a glass tube airtight. The method they used was attributed to their legendary patron, Hermes Trismegistus — hence the description ‘hermetically sealed.’

Hermetic seals are airtight seals that prevent the passage of gases or liquids. Airplanes in flight are hermetically sealed to prevent air from escaping. The International Space Station is hermetically sealed and astronauts on spacewalks are similarly protected. The food industry relies on hermetically sealed packaging to exclude air that can lead to deterioration. Hermetic seals are used in electronic equipment to keep out moisture as well as for archiving historical documents such as the United States Constitution, the Bill of Rights and the Declaration Of Independence, which have been sealed with argon since 2003.

In some versions of the legend, Hermes Trismegistus was not a god but an ancient Egyptian alchemist who had taken his name from Hermes and was buried in a chamber in the Great Pyramid of Giza. Some of the powerful secrets of alchemy were supposedly found inscribed on the Emerald Tablet found clutched in the hands of his mummy. This tablet was thought to be the key for transmuting base materials to precious metals and gems. Its translator was the 8th century alchemist Jabir ibn Hayyan, from whose name the term ‘gibberish’ is derived, reflecting the confusing writings of the alchemists. 

Alchemists believed in transmutation, or the conversion of certain substances to gold. Jabir himself was convinced that yellow sulphur and silvery mercury would combine to form gold. He carried out many such experiments and, like other alchemists, recorded his results in elaborate codes to protect his intellectual­ property. Anyone reading his writings would see them as gibberish. But Jabir gave us more than gibberish. In his attempts to make gold he mastered the techniques of sublimation and distillation and learned to prepare many simple chemicals. He also argued that alchemy should be taught at universities. This ran against the teachings of the church, which maintained that alchemy was sinful because its practitioners sought the divine power of creation. But Jabir argued that if humans had the wisdom to create new substances, it was because God had given them the ability to do so. 

As far as the Emerald Tablet goes, an English translation was provided by Isaac Newton, who was infatuated with alchemy and possibly had mercury poisoning from attempting to produce gold. Newton wrote, “that which is below is like that which is above and that which is above is like that which is below to do the miracles of one only thing and as all things have been and arose from one by the mediation of one, so all things have their birth from this one thing by adaptation.” It isn’t hard to see why alchemical writings are regarded as gibberish. Newton’s possible mercury poisoning is supported by the high levels of mercury and lead in a hair sample kept at Trinity College, Cambridge. Hopefully it is hermetically sealed to keep it from deteriorating.

Joe Schwarcz is the director of McGill University’s Office for Science and Society. 
Read his blog at