The Net (substance) The Net (substance) The Net, in alchemy, is an alloy of copper and iron, whose crystal structure induces a network pattern on its surface. It was described in the 17th century by Sir Isaac Newton. Newton produced the substance by following what he regarded as a recipe, encoded in classical mythology, for part of the process of achieving the philosopher's stone. The relevant myth involved the god Vulcan finding his wife Venus (alchemical symbol for copper) in bed with the god Mars (alchemical symbol for iron) Newton's interpretation rested on typical alchemical associations, construing Vulcan as a stand-in for fire,
Substance of very high concern use these substances, manufacturers, importers and users in the European Union (EU) need to apply for authorization from the ECHA. This list is referred to as the "candidate" list because all substances placed on it are candidates for inclusion in Annex XIV of REACH. If a substance is added to Annex XIV, it is given a "latest application date" and a "sunset date". The sunset date is the date after which the substance cannot be used or imported into the EU without authorisation from the ECHA, and the latest application date is the date by which any applications for use