  In this paper we study Butson Hadamard matrices, and codes over finite rings
coming from these matrices in logarithmic form, called BH-codes. We introduce a
new morphism of Butson Hadamard matrices through a generalized Gray map on the
matrices in logarithmic form, which is comparable to the morphism given in a
recent note of \'{O} Cath\'{a}in and Swartz. That is, we show how, if given a
Butson Hadamard matrix over the $k^{\rm th}$ roots of unity, we can construct a
larger Butson matrix over the $\ell^{\rm th}$ roots of unity for any $\ell$
dividing $k$, provided that any prime $p$ dividing $k$ also divides $\ell$.
  We prove that a $\mathbb{Z}_{p^s}$-additive code with $p$ a prime number is
isomorphic as a group to a BH-code over $\mathbb{Z}_{p^s}$ and the image of
this BH-code under the Gray map is a BH-code over $\mathbb{Z}_p$ (binary
Hadamard code for $p=2$). Further, we investigate the inherent propelinear
structure of these codes (and their images) when the Butson matrix is cocyclic.
Some structural properties of these codes are studied and examples are
provided.
