  High and low resolution $IUE$ spectra of V838 Her in the early outburst
stages exhibit a strong absorption feature shortward of $\lambda$3130. We
discuss the nature of this spectral feature and provide convincing evidence
that it corresponds to the blue-shifted resonance doublet of singly-ionized
$^7$Be, recently discovered in other novae. During the evolution of the
outburst the appearance of an emission feature close to $\lambda$3130 is also
identified as $^7$Be II $\lambda$3132 because the usual identification as the O
III $\lambda$3133.7 Bowen fluorescence line is hardly compatible with both the
known oxygen under-abundance in the nova ejecta and the low optical depths in
the nebula due to the high outflow velocity. The average $^7$Be abundance
relative to hydrogen, estimated by four different methods, i.e. the $^7$Be II /
Mg II absorption ratio, and the $^7$Be II / Mg II, $^7$Be II / He II$_{1640}$,
and $^7$Be II / H$\beta$ emission ratios is N(Be)/N(H) $\approx$ 2.5 $\times
10^{-5}$ (by number), i.e. $\approx$ 1.7 $\times 10^{-4}$ by mass. This
corresponds to an overproduction of $^7$Be by about 1 dex in comparison with
the theoretical models of massive CO and ONe novae. Since $^7$Be all converts
into $^7$Li, the $^7$Be/H abundance implies a $^7$Li/H overabundance of about 4
dex over the $^7$/H meteoritic value and indicates a total ejected mass of
$^7$Li of $\approx$ 9.5$\times$10$^{-10}$ $M_{\odot}$. These data are in line
with previous observations and indicate that large amounts of $^7$Li can be
synthesized in a variety of novae, including very fast ONe novae.
