  The optical conductivity of graphite in quantizing magnetic fields is
analytically evaluated for frequencies in the range of 10--300 meV, where the
electron relaxation processes can be neglected and the low-energy excitations
at the "Dirac lines" are more essential. The conductivity peaks are explained
in terms of the electron transitions in graphite.
  Conductivity calculated per one graphite layer tends on average to the
universal conductivity of graphene while the frequency is larger than the
Landau spacing.
  The (semi)metal-insulator transformation is possible under doping in high
magnetic fields.
