In a previous report [Phys. Lett. A 216, 178 (1996)] we phenomenologically
considered the conduction mechanism of a highly disordered carbon system. I
n this article a metal-insulator transition is investigated based on our th
eory for the disordered system. Our results for the temperature-dependent c
onductivity show an apparent metal-insulator transition and are in good agr
eement with experimental results in disordered carbons.