  We report the successful buffer-gas cooling and magnetic trapping of chromium
atoms with densities exceeding $10^{12}$ atoms per cm$^{3}$ at a temperature of
350 mK for the trapped sample. The possibilities to extend the method to
buffer-gas cool and magnetically trap molecules are discussed. To minimize the
most important loss mechanism in magnetic trapping, molecules with a small
spin-spin interaction and a large rotational constant are preferred. Both the
CrH ($^6\Sigma^+$ ground state) and MnH ($^7\Sigma^+$) radicals appear to be
suitable systems for future experiments.
