  In an attempt of clarifying the connection between the photospheric abundance
anomalies and the stellar rotation as well as of exploring the nature of
"normal A" stars, the abundances of seven elements (C, O, Si, Ca, Ti, Fe, and
Ba) and the projected rotational velocity for 46 A-type field stars were
determined by applying the spectrum-fitting method to the high-dispersion
spectral data obtained with BOES at BOAO. We found that the peculiarities
(underabundances of C, O, and Ca; an overabundance of Ba) seen in slow rotators
efficiently decrease with an increase of rotation, which almost disappear at
v_e sin i > 100 km s^-1. This further suggests that stars with sufficiently
large rotational velocity may retain the original composition at the surface
without being altered. Considering the subsolar tendency (by several tenths dex
below) exhibited by the elemental abundances of such rapidly-rotating
(supposedly normal) A stars, we suspect that the gas metallicity may have
decreased since our Sun was born, contrary to the common picture of galactic
chemical evolution.
