The link between Taylor dispersion and irreversible thermodynamics pointed out by Camacho [Phys. Rev. E 47, 1049 (1993)] is substantiated through the study of the thermodynamic functions associated to Taylor dispersion. They are evaluated by two means. First, from the connection between the one-dimensional (1D) thermodynamic functions of extended thermodynamics-entropy, entropy flux, entropy production, and chemical potential-and the constitutive equations describing the dynamics of the Taylor flux components; and second, from a purely thermodynamic analysis in the three-dimensional (3D) space. Both independent procedures are shown to yield the same results, thus confirming the physical entity of the Taylor thermodynamic functions. The different interpretation of the same physical quantities given by 3D and 1D observers is thoroughly discussed. © 1993 The American Physical Society.