No person shall at the same time be a member of more than one of the following bodies, to-wit--: the city councils, the guardians of the poor, the board of health, the controllers of the public schools, the directors of the public schools, and the inspectors of the county prison, nor shall any person be a member of any of these bodies, who is at the same time a salaried officer under the same or under any of them: Provided, That this shall not be construed so as to prevent a controller of the public schools from being at the same time a school director.