  Infrared reflection and transmission as a function of temperature have been
measured on single crystals of Cu$_{3}$Bi(SeO$_{3}$)$_{2}$O$_{2}$Cl. The
complex dielectric function and optical properties along all three principal
axes of the orthorhombic cell were obtained via Kramers-Kronig analysis and by
fits to a Drude-Lorentz model. Below 115 K, 16 additional modes
(8(E$\parallel\hat{a}$)+6(E$\parallel\hat{b}$)+2(E$\parallel\hat{c}$)) appear
in the phonon spectra; however, powder x-ray diffraction measurements do not
detect a new structure at 85 K. Potential explanations for the new phonon modes
are discussed. Transmission in the far infrared as a function of temperature
has revealed magnetic excitations originating below the magnetic ordering
temperature ($T_{c}\sim$24 K). The origin of the excitations in the
magnetically ordered state will be discussed in terms of their response to
different polarizations of incident light, behavior in externally-applied
magnetic fields, and the anisotropic magnetic properties of
Cu$_{3}$Bi(SeO$_{3}$)$_{2}$O$_{2}$Cl as determined by d.c. susceptibility
measurements.
