  We compute quantum corrections to soliton masses in affine Toda theories with
imaginary exponentials based on the nonsimply-laced Lie algebras $c_n^{(1)}$.
We find that the soliton mass ratios renormalize nontrivially, in the same
manner as those of the fundamental particles of the theories with real
exponentials based on the nonsimply-laced algebras $b_n^{(1)}$. This gives
evidence that the conjectured relation between solitons in one Toda theory and
fundamental particles in a dual Toda theory holds also at the quantum level.
This duality can be seen as a toy model for S-duality.
