  We study the third order pion-nucleon scattering amplitude obtained from
heavy baryon chiral perturbation theory inside the Mandelstam triangle. We
reconstruct the pion-nucleon amplitude in the unphysical region by use of
dispersion relations and determine the pertinent low-energy constants by a fit
to this amplitude. A detailed comparison with values obtained from phase shift
analysis is given. Our analysis leads to a pion-nucleon sigma-term of sigma(0)
= 40 MeV based on the Karlsruhe partial wave analysis. We have repeated the
same procedure using the latest solution of the VPI group and find a much
larger value for sigma(0).
