\begin{table}%t1
\caption{Composition of the dust mixture in the outer regions of a
protoplanetary accretion disk according to Pollack et~al. (\cite{Pol94}). The
table shows the fraction of the indicated elements condensed into the
different dust species. $x$ denotes the mole fraction of the pure magnesium
silicate end members of the solid solution series forming the
magnesium-iron-silicates called olivine-type and pyroxene-type,
respectively, on the basis of their assumed chemical composition. Only 
those dust components of the most abundant refractory elements are
considered that are the main sources of dust opacity.}\label{TabMixtP94}
%\centering
\par
\begin{tabular}{lllllllc}
\hline
\hline
Species && Mg & Fe & Si & S & C & $x$ \\
\quad formula\\
\hline
olivine-type  && 0.83 & 0.42 & 0.63 &      &      & 0.7 \\
\quad Mg$_{2x}$Fe$_{2(1-x)}$SiO$_4$&\\
pyroxene-type && 0.17 & 0.09 & 0.27 &      &      & 0.7 \\
\quad Mg$_x$Fe$_{1-x}$SiO$_3$ &\\
quartz-type   &&      &      & 0.10 &      &      &     \\
\quad SiO$_2$&\\
iron     &&      & 0.10 &      &      &      &     \\
\quad Fe&\\
troilite &&      & 0.39 &      & 0.75 &      &     \\
\quad FeS&\\
kerogen &&      &      &      &      & 0.55 &     \\
\quad CHON-material\\
\hline
\end{tabular}
\end{table}