  We verify for the first time the reciprocal relation between the spin Peltier
and spin Seebeck effects in a bulk YIG/Pt bilayer. Both experiments are
performed on the same YIG/Pt device by a setup able to accurately determine
heat currents and to separate the spin Peltier heat from the Joule heat
background. The sample-specific value for the characteristics of both effects
measured on the present YIG/Pt bilayer is $(6.2 \pm 0.4)\times 10^{-3} \,\,
\mbox{KA$^{-1}$}$. In the paper we also discuss the relation of both effects
with the intrinsic and extrinsic parameters of YIG and Pt and we envisage
possible strategies to optimize spin Peltier refrigeration.
