  The spin flip of the conduction electrons at the interface of a ferromagnetic
and a nonmagnetic part of a metallic wire, suspended between two electrodes, is
shown to tort the wire when a current is driven through it.
  In order to enhance the effect it is suggested to use an alternating current
in resonance with the torsional oscillations.
  Thereby the magnetic polarization of the conduction electrons in the
ferromagnet can be measured directly, and compared to the total magnetization.
  This may yield new information on the transport properties of the narrow band
electrons in itinerant ferromagnets.
