  A treatise on the optical property of biological tissue is presented. Water
is postulated to be a topological basis and serves to discriminate published
skin data. Electromagnetic theory governing dielectric behavior is concisely
detailed pertaining to certain optical constants and Kramers-Kronig relation.
The Kramers-Kronig relation defining dispersion index is emulated through the
discrete Hilbert transform. An accrued absorption set is populated with
empirical absorption data for biological skin, pure liquid water and
interpolated values. Kramers-Kronig analysis of biological skin yields a
comprehensive description of the complex index of refraction from DC to x-ray
frequencies.
