The great contribution to plant physiology made by two Chinese scientists P.S. Tang and J.S. Wang in 1941 is recalled. Their pioneering paper " Thermodynamic formulation of water relation in an isolated living cell" was the first in the world to propose the water potential concept more than 20 years earlier than wes－tern scientists, but this contribution was ignored and forgotten for over 40 years. The main ideas of their paper, the historical background under which it was written, its subsequent neglect and the lessons we should draw from its fate are analyzed.