In the previous, paper the authors reported the experimental results of heat transfer rates between single particles and air due to natural convection, the specimens of which were small bead type thermistors. The correlation of N_u(L) and G_r(L) was extrapolated to that of N_u(L) and G_r(L)P_r, simply following the similarity law. In this paper, the authors have measured the heat transfer coefficient of small particles in the still liquids of different Prandtl Numbers and ascertained that the extrapolated correlation in the previous report holds good in the wide range of P_r as 0.71∼10⁵ which could be written as [numerical formula] where L=2 (volume)/(surface area), and N_{u, 0(L)}=the limiting Nusselt Number