  It is shown that a space-time hypersurface of a 5-dimensional Ricci-flat
space-time has its energy momentum tensor algebrically related to its extrinsic
curvature and to the Riemann curvature of the embedding space. It is also seen
that the Einstein-Maxwell field does not arise naturally from this geometry, so
that a Kaluza-Klein model based on it would require further assumptions.
