of cohesion of the liquid. [@Utkin2010]

A number of studies have looked at the effect of viscosity and strain rate on the cavitation threshold of liquids. Using a bullet-piston type experiment, Bull [@Bull1956] found an empirical power law relationship ($P_\mathrm{s}\sim \eta^{0.2}$) between dynamic viscosity ($\eta$) and the tension at the onset of cavitation ($P_\mathrm{s}$) for an assortment of liquids spanning four orders of magnitude in viscosity. The observed increase in the cavitation threshold with increasing viscosity was attributed to a larger resistance to viscous growth of voids. [@Bull1956] Couzens and Trevena [@Couzens1974] studied the relationship between spall strength and viscosity for silicone oils over a range of three orders of magnitude using bullet-piston experiments and found a similar, albeit less sensitive relationship between cavitation threshold and viscosity ($P_\mathrm{s}\sim \eta^{0.06}$). A comparison of critical tension measurements for glycerol obtained from the bullet-piston experiments of Bull [@Bull1956b] and the spall experiments of Erlich et al. [@Erlich1971], shows that the critical tension was seen to increase from approximately at bullet-piston strain rates ($\dot{\epsilon}\approx$) to at spall experiment strain rates ($\dot{\epsilon}\approx$). Grady developed an energy-based spall strength model involving the viscous growth of pre-existing bubbles in a liquid [@Grady1988], and showed relatively good agreement 