  We present observations of the Be II 313.0 nm resonance doublet in 14 halo
and old disk stars with metallicities ranging from [Fe/H]=-0.4 to about -3.0
obtained with the CASPEC spectrograph of the ESO 3.6m telescope at a FWHM about
8.6 km/s resolution. Abundances are derived by means of the synthetic spectra
technique employing Kurucz (1993) atmospheric models, with enhanced
alpha-elements and no overshooting. The derived abundances together with those
available in literature show that for -2.7 < [Fe/H] < -0.8 Be correlates
linearly with iron [Be] proportional to 1.07(+/- 0.08)[Fe/H], giving strength
to previous results. However, a steeper correlation is still possible at
metallicities lower than [Fe/H]<-1.4 with [Be] proportional to 1.6(+/-
0.44)[Fe/H]. When iron is replaced with oxygen, Be is found tracking closely
oxygen up to solar values, without signs of breaking in correspondence of the
onset of the Galactic disk. No evidence of intrinsic dispersion is found, ought
to the large errors involved in the Be abundance determinations, but for three
stars (HD 106516, HD 3795, HD 211998) a significant upper limit in the Be
abundance can be placed at about 1 dex below the mean trend of the Be-Fe
relation. For such stars non conventional mixing is required to explain Be
depletion. Be observations can be used to discriminate strongly Li-depleted
stars. These are the stars which show less Li than that expected by high energy
cosmic rays production as deduced from Be observations. The available Be
observations imply that some of the stars which contribute to the scatter in
the Li-Fe diagramme are Li-depleted stars.
