We present a special similarity of R(4n) which maps lattice points int
o lattice points. Applying this similarity, we prove that if a (4n - 1
)-polytope is similar to a lattice polytope (a polytope whose vertices
are all lattice points) in R(4n) then it is similar to a lattice poly
tope in R(4n-1), generalizing a result of Schoenberg [4]. We also prov
e that an n-polytope is similar to a lattice polytope in some R(N) if
and only if it is similar to a lattice polytope in R(2n+1), and if and
only if sin(2)(angle ABC) is rational for any three vertices A, B, C
of the polytope.