The sole report of glycerin-water viscosities at high shear rates, by Ram, has so far been interpreted as evidence of shear thinning. Two alternative interpretations, both of which invoke experimental artifacts, have now been explored. One of these, viscous dissipation, qualitatively explains the progressive fall in the viscosity of glycerin-water as the shear rate is ramped-up beyond 60 000 s(-1) to 90 000 s(-1). New measurements with parallel disks separated by a narrow gap indicate that the viscosity of 60 wt % glycerin in water is constant up to 90 000 s(-1).