Comment on chirosorb as an invisible medium (and reply)

These comments are intended to clarify certain statements made in a recent paper (see ibid., vol.25, no.3, p.173, 1989) concerning the identification of a particular chiral half-space as an ´invisible medium´. The idea presented by the authors does not seem novel; in fact some researchers have pursued the investigation of a chiral absorber under real-life constraints such as bandwidth, aspect angles, polarisation dependence, thickness of the coating, etc., not just normal incidence on a half-space as done by the authors. Each point of the comments is discussed.