Appeal from decision of the Workmen’s Compensation Board. The deceased husband of the claimant was employed as a stationary engineeer. On August 14, 1948, there is proof that the deceased inhaled gas while cleaning an oven. He died three days later due to coronary thrombosis. There is proof the inhalation of gas contributed to the thrombosis and to his death; there is proof by two doctors and an impartial specialist that gas did not contribute to the death. The board found against claimant and disallowed benefits. The expression of positive opinion by a physician on a medical question does not amount to proof of such bias or prejudice that as a matter of law a court would require the rejection of his testimony. There is, besides this, other proof in this direction which the board was free to accept. Its determination is not open to our revision on the record presented to us. Decision affirmed, without costs. Foster, P. J., Brewster, Bergan and Halpern, JJ., concur.