Cohesion theory

  • Strasburger

    Conducted experiments showing that a tall oak tree trunk, severed at the base, could draw poisons and dyes up to the leaves by some wick-like action. if metabolism energised sap flow, poison should have inhibited it.
  • Dixon and Joly

    Claimed that very pure water molecules would be held together by powerful cohesional forces provided the water was exceptionally clean.
  • Professor EJ Ewart

    Conducted investigations which led him to conclude that 'the ascent of water is therefore a vital problem insofar as it depends upon conditions which hitherto can only be maintained in living wood'
  • Dixon

    Postulated the Cohesions Theory, based on those properties of water which distinguish it as an ideal biological solvent. Through the evaporative power of the atmosphere, a continuous 'chain' of water, well below atmospheric pressure, could be drawn up to a leaf canopy.