This proposal is devoted to complete 2.5-45 micron spectroscopy, using SWS01,
of a sample of IR sources embedded in molecular clouds.  These sources are
proposed because (i) ground-based observations detect a deep water ice band
at 3.07 micron (ii) they have not been previously observed at wavelengths
inaccessible to ground-based observations and (iii) existing ISO observations
of these sources only cover very specific SWS06 ranges.  With SWS01, the
resolution is well adapted to solid state features and we aim at detecting
H2O, CO, CO2, CH4 plus other less abundant molecules.  Our spectra will be
compared with laboratory spectra of various ices in order to derive solid
state molecular abundances, in simple molecules as well as in the silicate
bands. As a byproduct we hope to measure the absorption expected from
polycyclic aromatic hydrocarbons so as to provide a means of deriving their
abundance.