Pison
   Babylonian, the current, broad-flowing, one of the "four heads"
   into which the river which watered the garden of Eden was
   divided (Gen. 2:11). Some identify it with the modern Phasis,
   others with the Halys, others the Jorak or Acampis, others the
   Jaab, the Indus, the Ganges, etc.

	

	Pison, changing; extension of the mouth