http://arxiv.org/pdf/gr-qc/9909014v1.pdf Steve Carlip: "It is well known that the deflection of light is twice that predicted by Newtonian theory; in this sense, at least, light falls with twice the acceleration of ordinary "slow" matter."
This implies that, in 1919, Eddington's results rejected the variation of the speed of light predicted by Newton's emission theory and confirmed the twice-as-great variation predicted by Einstein's general relativity. Is that true? Of course not. First, Eddington fudged the results - the effect was actually too small for him to have discerned. Second, forty years later, the Pound-Rebka experiment unequivocally showed that light falls with the acceleration of ordinary matter, as predicted by Newton's emission theory of light:
http://www.einstein-online.info/spotlights/redshift_white_dwarfs Albert Einstein Institute: "...you do not need general relativity to derive the correct prediction for the gravitational redshift. A combination of Newtonian gravity, a particle theory of light, and the weak equivalence principle (gravitating mass equals inertial mass) suffices. (...) The gravitational redshift was first measured on earth in 1960-65 by Pound, Rebka, and Snider at Harvard University..."