  Applying standard mathematical methods, it is explicitly shown how the
Riccati equation for the Hubble parameter H(\eta) of barotropic open FRW
cosmologies is connected with a Korteweg-de Vries equation for adiabatic index
solitons. It is also shown how one can embed a discrete sequence of adiabatic
indices of the type n^2({3/2}\gamma -1)^2 (\gamma \neq 2/3) in the sech FRW
adiabatic index soliton
