stone groundwood 45 percent balsam fir 50 percent spruce and 5 percent jack pine the pulp was stored at headbox consistency in 19 1 polyethylene containers at 5 u00b0 c prior to use the pulp was successively centrifugated decantated and redispersed in distilled water to 250 g of newsprint headbox pulp at 50 u00b0 c was added 5 ml of 0 05 reax 85a solution the mixture was gently stirred in a water bath at 50 u00b0 c a dilute poly oxyethylene solution was prepared by adding 2 ml of stock solution to 243 g of water at 50 u00b0 c and this was added to the pulp suspension after two minutes stirring in the water bath the pulp suspension was added to the dynamic retention drainage jar where it was stirred a further two minutes at 500 rpm after which the valve was released and the white water was collected in a beaker the consistency solids content of the white water was determined gravimetrically after filtration and drying of the filtered mat at 105 u00b0 c the first pass retention was calculated by the following formula in which c i is the consistency of the pulp added to the dynamic retention drainage jar and c ww is the white water consistency equ1 the results for a series of polymer concentrations are summarized in table i in the absence of poly oxyethylene the reax 85a did not increase fines retention and in the absence of the reax 85a the poly oxyethylene did not increase fines retention by contrast the mixture of poly oxyethylene and reax 85a did increase the retention of fines in what appears to be a synergistic.