We report the measurement of electric conductivity in two cyanobiphenyls 7CB and 8CB. The alignment has been achieved using an electric field. We report that for 7CB the anisotropy in conductivity is positive at ail temperatures. For 8CB too, we find that Delta sigma is positive both in the nematic and the smectic phase. This is in sharp contradiction with what has been found in most smectics and particularly with the work of Jadzyn and Kedziora(5) for 8CB.