Elements in Medieval alchemy
The elemental system used in Medieval alchemy was developed by the Arabic alchemist Jābir ibn Hayyān and others. His original system consisted of the four classical elements found in the ancient Greek traditions (air, earth, fire and water), in addition to two philosophical elements: sulphur, ‘the stone which burns’, which characterized the principle of combustibility, and mercury, which contained the idealized principle of metallic properties.
The three metallic principles: sulphur to flammability or combustion, mercury to volatility and stability, and salt to solidity. became the tri prima of the Swiss alchemist Paracelsus, who reasoned that Aristotle’s four element theory appeared in bodies as three principles.
Paracelsus saw these principles as fundamental, and justified them by recourse to the description of how wood burns in fire. Mercury included the cohesive principle, so that when it left in smoke the wood fell apart. Smoke described the volatility (the mercury principle), the heat-giving flames described flammability (sulphur), and the remnant ash described solidity (salt).
Modern science recognizes classes of elementary particles which have no substructure (or rather, particles that aren’t made of other particles) and composite particles having substructure (particles made of other particles). The Standard Model of quantum mechanics defines three classes of elementary subatomic particles: quarks and leptons (matter-like particles) and gauge bosons (energy-like force carriers). Quarks are divided into six types: up, down, top, bottom, strange and charm; and leptons are similarly divided into six types: electron, electron neutrino, muon, muon neutrino, tau and tau neutrino. The types of force carriers include: photon, W and Z boson, gluon and some quantification of a Higgs boson.