\begin{table}%t4
\caption{\label{TabHI}HI, H$_2$ and total hydrogen column densities.}
%\centerline
{\small
\begin{tabular}{l @{\hspace{0.3cm}} r @{\hspace{0.3cm}} r @{\hspace{0.3cm}}
 r @{\hspace{0.3cm}} r @{\hspace{0.3cm}} r}
\hline\hline\noalign{\smallskip}
            & $\upsilon_0$         & $\Delta \upsilon$    & $N$(H)\tablefootmark{a} & $N({\rm H}_2)^{c}$ & $N_{\rm H}^{d}$ \\
Source      & (\kms) & (\kms) & (cm$^{-2}$) & (cm$^{-2}$) & (cm$^{-2}$) \\
            &               &               & $\times 10^{21}$ & $\times 10^{21}$ & $\times 10^{21}$ \\
\hline
{\bf W51}   &
$\left. \begin{array}{r r r}   6.2 \\  11.8 \end{array} \right. $ & 
$\left. \begin{array}{r r r}   5.6 \\   6.0 \end{array} \right. $ &
$\left. \begin{array}{r r r}  1.27 \\  0.58 \end{array} \right. $ &
0.47 & 2.3 \\
\\
\hline\noalign{\smallskip}
            & $\upsilon_{\rm min}$ & $\upsilon_{\rm max}$ & $N$(H)\tablefootmark{b} & $N({\rm H}_2)^{c}$ & $N_{\rm H}^{d}$ \\
Source      & (\kms) & (\kms) & (cm$^{-2}$) & (cm$^{-2}$) & (cm$^{-2}$) \\
            &               &               & $\times 10^{21}$ & $\times 10^{21}$ & $\times 10^{21}$ \\
\hline\noalign{\smallskip}
{\bf G05.88-0.39} & 
$\left. \begin{array}{r r r} -31.3 \\ -10.0 \\  4.0 \\  20.0 \end{array} \right. $ & 
$\left. \begin{array}{r r r} -10.0 \\   4.0 \\ 20.0 \\  29.3 \end{array} \right. $ &
$\left. \begin{array}{r r r}  1.59 \\ {>}6.68 \\ 5.87 \\ {>}3.86 \end{array} \right. $ &
 & 16 \\
\\
{\bf G08.67-0.36} & 
$\left. \begin{array}{r r r}  -1.7 \\  11.3 \\  25.7 \end{array} \right. $ & 
$\left. \begin{array}{r r r}  11.3 \\  25.7 \\  45.3 \end{array} \right. $ &
$\left. \begin{array}{r r r}  4.80 \\  5.32 \\ {>}9.62 \end{array} \right. $ &
 & 14 \\
\\
{\bf G10.62-0.38} &
$\left. \begin{array}{r r r}  11.3 \\  25.0 \\ 30.6 \end{array} \right. $ & 
$\left. \begin{array}{r r r}  25.0 \\  30.6 \\ 47.3 \end{array} \right. $ &
$\left. \begin{array}{r r r}  3.53 \\  2.61 \\ 5.54 \end{array} \right. $ &
15.8 & 17 \\
\\
{\bf G34.3+0.1}   &
$\left. \begin{array}{r r r}  -2.5 \\   7.1 \\ 20.0 \end{array} \right. $ & 
$\left. \begin{array}{r r r}   7.1 \\  20.0 \\ 34.1 \end{array} \right. $ &
$\left. \begin{array}{r r r}  0.54 \\  2.01 \\ 4.42 \end{array} \right. $ &
 & 9 \\
\\
{\bf W49N}        &
$\left. \begin{array}{r r r}  30.0 \\  50.0 \end{array} \right. $ & 
$\left. \begin{array}{r r r}  50.0 \\  78.2 \end{array} \right. $ &
$\left. \begin{array}{r r r}  6.95 \\  7.23 \end{array} \right. $ &
$\left. \begin{array}{r r r}   1.6 \\   4.0 \end{array} \right. $ &
23 \\
\hline
\end{tabular}}
\tablefoot{\tablefoottext{a}{Gaussian decomposition from Koo (\cite{Koo1997}). The column densities
  have been scaled to a spin temperature of 100~K.}
\tablefoottext{b}{Inferred from the absorption profiles observed by Fish et~al. (\cite{Fish2003}) with the VLA interferometer. A spin temperature of 100~K is assumed.}
\tablefoottext{c}{Estimation from the CH emission lines observed by Rydbeck et~al. (\cite{Rydbeck1976}) toward W51 and W49N, the CH absorption lines observed by Gerin \etal (in prep.) toward G10.62-0.38, and the correlation between CH and H$_2$, $N({\rm CH})/N({\rm H}_2) = 4.3 \times 10^{-8}$ (Liszt \& Lucas \cite{Liszt2002}).}
\tablefoottext{d}{From models of the extinction at 2~$\mu$m by Marshall et~al. (\cite{Marshall2006}).}}\vspace*{-2mm}
\end{table}