\begin{table}%t1
\caption{Molecular hydrogen abundances 
and dust contents $\tilde{k}$ in cosmological H$_2$-bearing clouds.}
\label{tab1}
%\centerline
$${
\begin{tabular}{l c r @{$\;\pm\;$} l c c c l}
\hline
\hline
\multicolumn{1}{c}{QSO} & \zabs & 
\multicolumn{2}{c}{$\log N$(\ion{H}{i})} &   
$\log N$(H$_2$) &   
$\log f_{{\rm H}_2}$ & $\tilde{k}^\ast$ &   
H$_2$ detection \\
\hline
$0515-4414$ & 1.151 &19.88&0.05 & $16.94^{+0.23}_{-0.41}$ 
& $-2.64^{+0.30}_{-0.27}$ & $0.89\pm0.19$ & this paper\\
$0551-366$ & 1.962 & 20.50&0.08 & $17.42^{+0.63}_{-0.90}$
& $-2.78^{+0.64}_{-0.90}$ & $2.12\pm0.48$ & Ledoux et~al. (\cite{Led02})\\ 
$0013-004^a$ & 1.973 & 20.70&0.05 & $19.84^{+0.10}_{-0.10}$ 
& $-0.66^{+0.10}_{-0.10}$ & $0.52\pm0.10$ & Ge \& Bechtold (\cite{Ge97})\\
$1444+014$ & 2.087 &  20.07&0.07 & $18.30^{+0.37}_{-0.37}$
& $-1.48^{+0.38}_{-0.38}$  & $0.77\pm0.30$ & Ledoux et~al. (\cite{Led03})\\
$1232+082$ & 2.338 & 20.90&0.10$^b$ &  $\geq$$17.19^c$ &  $\geq$$-3.41^c$ & $0.35\pm0.12$ & Ge et~al. (\cite{Ge01})\\
$0841+129$ & 2.374 & 20.95&0.10$^c$ & $14.56^\dagger$ & $<$$-5.98$ & $0.024\pm0.005$ & Petitjean et~al. (\cite{Pet00})\\
$0405-443$ & 2.595 & 20.90&0.10 & $18.16^{+0.21}_{-0.06}$ & $-2.44^{+0.23}_{-0.12}$ & $0.17\pm0.06$
& Ledoux et~al. (\cite{Led03})\\
$0528-250$ & 2.811 & 21.35&0.10$^{d,e}$ & $^c18.22^{+0.23}_{-0.16}$ & $^c-2.83^{+0.25}_{-0.19}$ &
$0.29\pm0.08$ & Levshakov \& Varshalovich (\cite{Lev85})\\
$0347-3819$ & 3.025 & 20.63&0.01 & $14.61^{+0.02}_{-0.02}$ & $-5.71^{+0.02}_{-0.02}$ & $0.068\pm0.013$
& Levshakov et~al. (\cite{Lev02}) \\
$0000-2620$ & 3.390 & 21.41&0.08$^f$ & $^g13.94^\dagger$ & $\simeq$$ -7.2$ & $\leq$$ 0.002$ &
Levshakov et~al. (\cite{Lev00})\\
\hline
\end{tabular}}$$
\medskip
Note: column densities $N$(\ion{H}{i}) and $N$(H$_2$) are given in \cm;
$^\dagger$ tentative H$_2$ identification; $^\ast$ photospheric solar   
abundances for Cr and Zn are taken from Grevesse \& Sauval (\cite{Gre98}), for
Mg and Fe from Holweger (\cite{Hol01}), 
see Eq.~(\ref{eq:E3}).\\
$^a$ High resolution UVES data reveal a few H$_2$ subcomponents
spread over $\sim$$700$~\kms\ (Petitjean et~al. \cite{Pet02}); 
$^b$ Srianand et~al. (\cite{Sri00}); $^c$ Ledoux et~al. (\cite{Led03}); $^d$ Levshakov \& Foltz (\cite{Lev88}); $^e$ M$\o$ller \& Warren (\cite{Mol93}); 
$^f$ Prochaska \& Wolfe (\cite{Pro99}); $^g$ Levshakov et~al. (\cite{Lev01}). 
\end{table}