The antiviral activity in tissue culture, in chick embryo, and in mice of a-keto aldehyde derivatives of biphenyl, diphenylmethane, diphenylethane, stilbene, diphenyl ether, diphenyl sulfide, and diphenyl sulfone was studied. Several substances were found active in chick embryo against A-PR8 virus, in tissue culture against poliomyelitis virus, adenovirus, and vaccinia virus. All substances were active in mice against MHV3 virus and nonactive ...