  A 5th force coupling to baryon number $B$ has been proposed to account for
the correlations between the acceleration differences $\Delta a_{ij}$ of the
samples studied in the E\"{o}tv\"{o}s experiment, and the corresponding
differences in the baryon-to-mass ratios $\Delta(B/\mu)_{ij}$. To date the
E\"{o}tv\"{o}s results have not been supported by modern experiments. Here we
investigate the phenomenological implications of a possible magnetic analog
$\vec{\mathscr{B}}_5$ of the conventional 5th force electric field,
$\vec{\mathscr{E}}_5$, arising from the Earth's rotation. We demonstrate that,
in the presence of couplings proportional to $\vec{\mathscr{B}}_5$, both the
magnitude and direction of a possible 5th force field could be quite different
from what would otherwise be expected and warrants further investigation.
