We report measurements of the viscosity near the consolute point of triethyl n-hexyl ammonium triethyl n-hexyl borate in diphenyl ether. Until recently, this ionic mixture was the leading candidate for a ''mean-field'' ionic fluid composed of small molecules. The measurements of the coexistence curve of Singh and Pitzer and the measurements of turbidity of Zhang et al. had indicated mean-field static behavior. In contrast, the present measurements show a critical viscosity enhancement similar to that seen in Ising fluids. Such an enhancement is not expected in either a mean-field fluid or a fluid with sufficiently long-ranged forces. The measurements were made in two very different viscometers. Both viscometers achieved low shear rates by use of a flow impedance larger than in a conventional capillary viscometer. The first viscometer's impedance was a glass frit consisting of about 10 5 pores of 5.5 m diam each. The second viscometer's impedance was a single 1 m long, 203 m diam capillary. In both viscometers, the sample was sealed entirely in glass, in order to inhibit decomposition of the sample.