In the 4-hydroxydiphenyl molecule the usual orienting effect of the hydroxyl group should open positions 3, 5, 4'to substitution. That substitution does follow the normal course, namely,(1) mono-ortho,(2) di-ortho, and (3) di-ortho-p'has been demonstrated by Bell and Robinson1 for nitration, and by Colbert and others2 for chlorination. The substitution reactions of 2-hydroxydiphenyl, in which postions 3, 5 are open, have been investigated ...